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An assessment of the bulk material quality of industrial Czochralski (Cz) grown phosphorus‐doped n‐type silicon (Si) wafers along an ingot is reported. The minority charge carrier lifetimes of the Cz‐Si wafer bulk before and after phosphorous (POCl3) diffusion gettering are assessed, by applying room‐temperature superacid surface passivation to avoid any additional gettering or hydrogenation effect. A substantial increase in the bulk lifetime of all of the n‐type Cz‐Si wafers along the ingot is observed, indicating the effectiveness of a gettering step for such wafers and the presence of getterable metallic impurities in these wafers. By experimentally monitoring the lifetime changes upon a gettering anneal and simulating the gettering kinetics based on different metal diffusivities, iron is identified to be a limiting defect, at least for the wafers from the tail part of the ingot. A dissolved iron concentration of (8±2) ×1011 cm−3$\left(\right. 8 \pm 2 \left.\right) \textrm{ } \times \left(10\right)^{11} \left(\text{ cm}\right)^{- 3}$ is estimated from the bulk lifetimes of the tail wafers. This lifetime kinetics approach is also a demonstration of a new method to identify iron, or other getterable metals with moderate diffusivities such as chromium, in n‐type silicon wafers. [ABSTRACT FROM AUTHOR]

Herein, a systematic study of the electronic quality of gallium‐doped p‐type silicon wafers from Czochralski‐grown ingots with melt recharging is presented. It is found that in the as‐grown state, the ingots contain interstitial iron concentrations in the range of 3 × 109–2 × 1010 cm−3, with a trend of slightly higher concentrations toward the tail end of each ingot, and in subsequently grown ingots. However, analysis of the effective lifetimes indicates that iron–gallium pairs are not the dominant recombination centers in the as‐grown state. Moreover, when these wafers are subjected to a tabula rasa step, an increase in the iron concentration is observed in the range of 1 × 1010–6 × 1010 cm−3, with iron–gallium pairs becoming the dominant recombination centers. This is possibly caused by the dissolution of pre‐existing precipitated iron in the wafers. Nevertheless, the negative impact of iron contamination can be dramatically reduced by subjecting the wafers to a phosphorus diffusion gettering step, as is commonly incorporated in the fabrication of p‐type passivated emitter and rear cells. Therefore, it is concluded that the quality of the ingots is not limited by iron contamination, even after multiple ingots are pulled from the recharged melt. [ABSTRACT FROM AUTHOR]

In addition to excellent surface passivation and carrier selectivity, the structure based on the heavily doped polysilicon layer on an ultrathin silicon oxide interlayer also demonstrates strong impurity gettering effects. Herein, the gettering strength of a range of phosphorus‐ or boron‐doped polysilicon films from different fabrication techniques is assessed and compared. Iron, one of the most common metallic impurities in silicon, is used as a tracer impurity to quantify the gettering strength (segregation coefficient). A comparison of the experimental results to the literature, combined with measurements of the electrically active and inactive dopant concentrations, enables us to suggest the main gettering mechanisms in different polysilicon films. The differences in the segregation coefficients of the phosphorus‐doped polysilicon films for iron are within one order of magnitude, in spite of their different combinations of gettering mechanisms. On the other hand, boron‐doped polysilicon films show a large variation in their gettering effects, although the predominant gettering mechanisms are all attributed to electrically inactive boron, according to the current understanding of the gettering mechanisms from the literature. Finally, the impact of different polysilicon gettering effects on the efficiency of tunnel oxide‐passivated contact (TOPCon) cells is simulated and discussed. [ABSTRACT FROM AUTHOR]

Black silicon (b‐Si) has many attractive properties and is currently being adopted in various fields of semiconductor technology. It is shown here that b‐Si during thermal activation may serve as an external gettering layer to remove metallic impurities and associated defects from bulk Si. The gettering efficiency by b‐Si is estimated according to the results of studying the resistivity, defect density, interstitial iron concentration, and effective minority carrier lifetime on gettered test and ungettered reference Si samples. It is shown that in the thermal oxidation process, the b‐Si layer serves as an effective drain for excess iron atoms and other fast‐diffusing impurities, thereby significantly reducing the density of oxidation‐induced stacking faults in Si. In addition, the resistivity of the substrates decreases, and the bulk carrier lifetime increases significantly. Finally, gettering by b‐Si is introduced into the solar cells fabrication process and its effect on solar cell current–voltage characteristics is investigated. It has been shown that all electronic parameters of the solar cells are improved. The conversion efficiency of ungettered solar cells is 16.8%, and for gettered solar cells, depending on the oxidation temperature, it increases by 1.36–1.96%. [ABSTRACT FROM AUTHOR]

Polycrystalline‐silicon/oxide (poly‐Si/SiOx) passivating contacts for high efficiency solar cells exhibit excellent surface passivation, carrier selectivity, and impurity gettering effects. However, the ultrathin SiOx interlayer can act as a diffusion barrier for metal impurities and this potentially slows down the overall gettering rate of the poly‐Si/SiOx structures. Herein, the factors that determine the blocking effects of the SiOx interlayers are identified and investigated by examining two general types of the SiOx interlayers: 1.3 nm ultrathin tunneling SiOx with negligible pinholes and 2.5 nm SiOx with thermally created pinholes. Iron is used as tracer impurity in silicon to quantify the gettering rate. By fitting the experimental gettering kinetics by a diffusion‐limited segregation gettering model, the blocking effects of the SiOx interlayers are quantified by a transport parameter. Both the oxide stoichiometry and pinhole density affect the effective transport of iron through SiOx interlayers. The oxide stoichiometry depends strongly on the oxidation method, while the pinhole density is affected by the activation temperature, doping concentration, doping technique, and possibly the dopant type as well. To enable a fast gettering process during typical high‐temperature formation of the poly‐Si/SiOx structures, a SiOx interlayer that is less stoichiometric or with a higher pinhole density is preferred. [ABSTRACT FROM AUTHOR]

It is known that the interstitial iron concentration in silicon is reduced after annealing silicon wafers coated with plasma-enhanced chemical vapour deposited (PECVD) silicon nitride films. The underlying mechanism for the significant iron reduction has remained unclear and is investigated in this work. Secondary ion mass spectrometry (SIMS) depth profiling of iron is performed on annealed iron-contaminated single-crystalline silicon wafers passivated with PECVD silicon nitride films. SIMS measurements reveal a high concentration of iron uniformly distributed in the annealed silicon nitride films. This accumulation of iron in the silicon nitride film matches the interstitial iron loss in the silicon bulk. This finding conclusively shows that the interstitial iron is gettered by the silicon nitride films during annealing over a wide temperature range from 250 ° C to 900 ° C, via a segregation gettering effect. Further experimental evidence is presented to support this finding. Deep-level transient spectroscopy analysis shows that no new electrically active defects are formed in the silicon bulk after annealing iron-containing silicon with silicon nitride films, confirming that the interstitial iron loss is not due to a change in the chemical structure of iron related defects in the silicon bulk. In addition, once the annealed silicon nitride films are removed, subsequent high temperature processes do not result in any reappearance of iron. Finally, the experimentally measured iron decay kinetics are shown to agree with a model of iron diffusion to the surface gettering sites, indicating a diffusion-limited iron gettering process for temperatures below 700 ° C. The gettering process is found to become reaction-limited at higher temperatures. [ABSTRACT FROM AUTHOR]

Substrate gettering and the contribution to the contamination reduction of backside layers are evaluated after high‐temperature annealing, following intentional iron contamination at the backside in silicon epitaxial wafers typical of power technologies. Iron is detected at the frontside by deep‐level transient spectroscopy within a depth corresponding to the actual devices. Herein, contamination occurring at the beginning of the semiconductor process flow is simulated and the role of the different gettering mechanisms is isolated. Substrate boron in epitaxial p over p+ wafers is effective in more than halving iron contamination at the front compared with a p‐only substrate, especially at high contamination doses. In the absence of a specific thermal cycle for oxygen precipitation and growth in the bulk, long thermal treatment at 1200 °C induces a significant precipitate growth even in the beginning of the process, greatly contributing to iron gettering in the bulk. However, this effect is found to strongly depend on the silicon condition after crystal growth. No significant contribution to iron gettering from a backside polycrystalline silicon layer is found after high‐temperature annealing, whereas a backoxide acts as diffusion barrier, effectively screening the substrate from contamination only for short thermal treatments or annealing temperature below 1000 °C. [ABSTRACT FROM AUTHOR]

• Calculations demonstrate the tendencies to the formation stable pairs of interstitial boron and phosphorous impurities in silicon. • The nature of high solubility and mobility of transitional metals atoms in Si were revealed. • Simulations demonstrate affinity of Fe, Co, Ni to B and P defects. • The mechanism of destruction stable B-P pairs due to charge redistribution near metal impurity were proposed. In this work, we report the results of the systematic studies of the interactions between boron and phosphorous impurities in silicon matrix and transitional metals (TM) co-dopants: iron, cobalt, and nickel. Calculations results demonstrate the favorability of the stable pairs of substitutional boron and phosphorous defects. Calculated energies of the formation of substitutional and interstitial TM defects explain the high solubility and mobility of this kind of impurity. The simulations also reveal reciprocal affinity between B, P, and TM impurities that leads to the migration of metal atoms toward boron and phosphorous defects. Redistribution of the charge density caused by the presence of TM in the neighboring position leads to a significant decrease in the energy cost for the migration of B and P substitutional impurities to the interstitial void. [ABSTRACT FROM AUTHOR]

Experiments have been conducted to understand the behaviour of iron in silicon containing oxide precipitates and associated defects (dislocations and stacking faults), which is subjected to phosphorus diffusion gettering. Injection-dependent minority carrier lifetime measurements are analysed to provide quantitative information on the degree to which the precipitates and associated defects are decorated with iron impurities. These data are correlated with bulk iron measurements based on the photodissociation of FeB pairs. Iron in the vicinity of oxide precipitates in samples with relatively low levels of bulk iron contamination (< 5 × 1012 cm–3) can be gettered to some extent. Higher levels of bulk iron contamination (> 1.2 × 1013 cm–3) result in irreversible behaviour, suggesting iron precipitation in the vicinity of oxide precipitates. Bulk iron is preferentially gettered to the phosphorus diffused layer opposed to the oxide precipitates and associated defects. [ABSTRACT FROM AUTHOR]

The efficacy of higher-temperature gettering processes in reducing precipitated iron concentrations is assessed by synchrotron-based micro-X-ray fluorescence. By measuring the same grain boundary before and after phosphorus diffusion in a set of wafers from adjacent ingot heights, the reduction in size of individual precipitates is measured as a function of gettering temperature in samples from the top of an ingot intentionally contaminated with iron in the melt. Compared to a baseline 820 °C phosphorus diffusion, 870 °C and 920 °C diffusions result in a larger reduction in iron-silicide precipitate size. Minority carrier lifetimes measured on wafers from the same ingot heights processed with the same treatments show that the greater reduction in precipitated metals is associated with a strong increase in lifetime. In a sample contaminated with both copper and iron in the melt, significant iron gettering and complete dissolution of detectable copper precipitates is observed despite the higher total metal concentration. Finally, a homogenization pre-anneal in N2 at 920 °C followed by an 820 °C phosphorus diffusion produces precipitate size reductions and lifetimes similar to an 870 °C phosphorus diffusion without lowering the emitter sheet resistance. [ABSTRACT FROM AUTHOR]

This paper presents direct experimental evidence for the strong impurity gettering effects associated with the formation of both phosphorus and boron doped polysilicon/oxide passivating contacts for silicon solar cells, doped via thermal diffusion from POCl 3 or BBr 3 sources. Ion-implanted iron is used as a marker to quantify the gettering effectiveness via carrier lifetime measurements. The process conditions for fabricating optimum polysilicon passivating contacts are found to remove more than 99.9% of the iron from the silicon wafer bulk. The gettering effects of POCl 3 and BBr 3 diffused polysilicon/oxide contacts mainly arise from the dopant diffusions, as opposed to gettering by structural defects in the polysilicon films. The thin oxide interlayer hinders the gettering effectiveness at low diffusion temperatures, although its blocking effect becomes small at the moderate temperatures used to fabricate optimum polysilicon contacts. The gettering effectiveness increases with increasing diffusion temperature. The gettering of iron from the silicon wafer bulk to the surface layers is found to have a negligible impact on their ability to suppress recombination at the interface with the silicon wafer. Therefore, the formation of polysilicon/oxide passivating contacts, via thermal diffusion from POCl 3 and BBr 3 sources, not only achieves high quality surface and contact passivation but also has the net additional benefit of achieving very effective gettering of unwanted impurities in the silicon wafer bulk. [ABSTRACT FROM AUTHOR]

Aluminium oxide (Al2O3) thin films deposited on silicon surfaces, synthesised by plasma‐assisted atomic layer deposition, are recently reported to possess impurity gettering effects for the silicon wafer bulk during annealing at 425 °C, a typical temperature used for activating the surface passivation quality of the Al2O3 films. This paper investigates the gettering effects of Al2O3 films at higher temperatures of 700–900 °C, which are commonly used for contact firing in silicon solar cell fabrication. Iron is used as a marker impurity in silicon to study the gettering effectiveness. Results show that Al2O3 films also generate strong impurity gettering effects at 700–900 °C, through a segregation gettering mechanism. The as‐deposited Al2O3 films are found to be more effective at gettering than the 425 °C‐activated Al2O3 films, demonstrating gettering processes that are largely limited by the impurity diffusivity in silicon. For both as‐deposited and activated Al2O3 films, gettering during high temperature annealing occurs by impurity accumulation at the Al2O3/Si interfaces, similar to the gettering action at 425 °C. However, some iron is found to redistribute into the bulk of the Al2O3 films after long annealing at a high temperature. [ABSTRACT FROM AUTHOR]

Between 10% and 30% of commercial cast silicon ingots is discarded due to contamination caused by the casting process. A significant contaminant in the scrap volume is metal precipitates, which are difficult to getter effectively and degrade minority charge carrier lifetime, hence limiting solar cell efficiency potential. We show here that the unusable red zone can be restored in high-performance multicrystalline silicon wafers. Adding a high temperature dissolution anneal prior to phosphorus diffusion dissolves the metal precipitates within the wafer bulk, and leaves the metal point defects in a mobile state to be readily gettered by phosphorus diffusion gettering during the solar cell process. The efficiency of the dissolution gettering treatment increases with increasing temperature, with a temperature of 1150 °C eliminating the very low lifetime region of the wafers completely. Additionally, we find that the red zone does not re-emerge after a 60 min oxidation anneal at 900 °C, confirming that the achieved benefit is tolerant to any high temperature processing following the phosphorus diffusion gettering process. [ABSTRACT FROM AUTHOR]

Si CMOS image-sensor (CIS) cells were designed by implementing proximity relaxation gettering sites of hydrogen-ion implantation-induced nanocavities (20–35 nm in diameter) underneath Si photodiode regions to enhance the sensing margin of output voltage in CIS cells. They enabled almost no degradation in the output voltage sensing margin, although ~ $ 10^{{\mathsf {14}}}$ cm $^{{\mathsf {-2}}}$ of Fe, Cu, Ni, and Co contaminants were introduced in the photodiode regions of CIS cells, demonstrating an excellent relaxation gettering ability. However, Si CIS cells designed with p/p++ epitaxial wafers, which are widely used, showed that the sensing margin of the CIS cells significantly decreased as the concentration of Cu and Ni contaminants in the Si photodiode regions increased, indicating no segregation gettering ability. [ABSTRACT FROM PUBLISHER]

In this study we investigate the efficacy of iron gettering as a function of electrically inactive phosphorus in the emitter in combination with low temperature annealing steps. To achieve different amounts of electrically inactive phosphorus in the emitter a highly doped PSG produced emitter with a large plateau depth of electrical active phosphorus is etched back stepwise by a wet-chemical procedure. Therewith we achieve a gradual reduction in electrically inactive phosphorus with small changes in electrically active phosphorus (ΔR sh < 4 Ω/sq). After this step, the wafers with different emitters have been annealed at 700 °C for 30 min and the content of Fe i in the bulk has been measured using QSS-PC. The results show, (i) that for higher amounts of electrically inactive phosphorusa stronger iron gettering effect can be observed and (ii) that an additional annealing step leads to a significant change of Fe i . This means, (i) that anelectricallyinactive phosphorus concentration dependence for iron gettering is observed and (ii) additional annealing steps, below the usual diffusion temperature of phosphorus, can be used to reduce interstitial iron in highly contaminated wafers further. [ABSTRACT FROM AUTHOR]

In this study we investigate the efficacy of iron gettering as a function of electrically inactive phosphorus in the emitter in combination with low temperature annealing steps. To achieve different amounts of electrically inactive phosphorus in the emitter a highly doped PSG produced emitter with a large plateau depth of electrical active phosphorus is etched back stepwise by a wet-chemical procedure. Therewith we achieve a gradual reduction in electrically inactive phosphorus with small changes in electrically active phosphorus (ΔRsh < 4 Ω/sq). After this step, the wafers with different emitters have been annealed at 700°C for 30 min and the content of Fei in the bulk has been measured using QSS-PC. The results show, (i) that for higher amounts of electrically inactive phosphorus a stronger iron gettering effect can be observed and (ii) that an additional annealing step leads to a significant change of Fei. This means, (i) that an electrically inactive phosphorus concentration dependence for iron gettering is observed and (ii) additional annealing steps, below the usual diffusion temperature of phosphorus, can be used to reduce interstitial iron in highly contaminated wafers further. [ABSTRACT FROM AUTHOR]

In this work we investigate the effect of the bulk metal contamination level in cast silicon on the electrical performance of PERC (passivated emitter and rear cell) solar cells [1] . The bulk contamination is varied in two different ways. In the first approach, cast silicon crystallized with high purity silicon feedstock and reduced metal contamination from crucible and coating is used. Second, an extended gettering step is introduced in the PERC process flow. The interstitial iron concentration is taken as a measure of the bulk metal contamination of the investigated cells. Both the higher purity cast silicon and the gettering step significantly lower the interstitial iron concentration in the resulting PERC cells. This clear positive effect is also mirrored in solar cell parameters such as the open circuit voltage U OC . In this experiment, the impact of gettering is larger than the effect which is reached by reducing the bulk metal concentration during the crystallization process. Device simulations show that most of the difference in U OC can be explained by the different interstitial iron levels while other recombination active defects might also be present. [ABSTRACT FROM AUTHOR]

The role of iron in crystalline silicon solar cells has been extensively investigated, yet the interaction mechanisms with structural defects have not been fully understood. In this work we have investigated a multicrystalline silicon ingot made in a small scale (1.5 kg) vertical gradient freeze (VGF) furnace with the addition of 50 ppma Fe in the polysilicon feedstock. The minority carrier lifetime was qualitatively measured by photoluminescence (PL). Grain morphology and -orientation were determined by electron backscatter diffraction (EBSD). The comparison between the PL and EBSD maps shows high lifetime areas near the grain boundaries, which is explained by an internal gettering mechanism. Furthermore, it is evident that Fe segregates slightly at coincidence site lattice (CSL) boundaries – especially at Σ3, while it segregates heavily at random grain boundaries. These results indicate the dependence of Fe segregation towards defect on grain boundary character. A method to qualitatively and quantitatively identify the segregation profiles and depleted region thickness is developed by image analysis. [ABSTRACT FROM AUTHOR]

This study involved developing a low-power and high-mobility metal–oxide thin-film transistor that incorporated a bilayer IGZO/IGZO:Ti semiconductor material. Compared with control metal–oxide TFTs, the bilayer IGZO TFT through thickness modulation of IGZO:Ti can reach the smallest subthreshold swing (85 mV/decade) and the highest field effect mobility (49 cm2/Vs) at a drive voltage of <3 V. This performance level improvement can be attributed to the gettering effect caused by the IGZO:Ti capping layer and its dual advantages, which enhance device mobility and improve gate swing. [ABSTRACT FROM PUBLISHER]

Abstract: We have studied the effect of thermal history on iron precipitation behavior in intentionally contaminated Czochralski silicon wafers that contain well-defined precipitation sites for iron, oxide precipitates. Iron precipitation was studied at a temperature range between 600°C and 700°C for various times. The results indicate that iron precipitation is strongly affected by the thermal history of the wafers. Our results also explain the disagreement observed previously in iron precipitation behavior at low temperature anneals. Finally, we discuss how the results can be applied to gettering in multicrystalline silicon. [Copyright &y& Elsevier]

Abstract: Different types of gettering treatments were applied to a real device process to evaluate their ability to remove iron contamination from the device layer and improve the electrical characteristics of the devices. NMOS and PMOS transistors and other test structures were manufactured on boron doped, both iron contaminated and uncontaminated Cz silicon wafers with or without gettering treatment. Gettering treatments, which were designed to induce sufficient iron precipitate nucleation in the bulk to ensure iron precipitation, were inserted in the fabrication process after the last high temperature treatment in which the iron solubility was higher than the contamination level. The electrical characteristics of the devices, such as leakage currents, were measured. The applied gettering treatments were found to be inefficient to improve the device performance, possibly due to stronger gettering to heavily doped, ion implantation damaged device layer. [Copyright &y& Elsevier]

Abstract: We have studied both experimentally and theoretically iron gettering behavior in silicon-on-insulator (SOI) wafers. We show that a deposition of a polysilicon layer between the buried oxide and the device layer is a convenient way to have an effective gettering layer for metals in bonded SOI wafers under various processing conditions. Both our experiments and simulations show that the polysilicon layer decreases the dissolved iron concentration in the device layer and most importantly decreases the precipitation of the metals on the wafer front surface. [Copyright &y& Elsevier]

Abstract: We report here the results of a theoretical study concerning the iron precipitation in multicrystalline silicon during crystal growth and its implications on phosphorus gettering. In our model the average size and density of iron precipitates in the final structure depends on the growth method, initial iron concentration and the density of possible heterogeneous precipitation sites. With the same model we can simulate phosphorus diffusion gettering (PDG) of iron in cast multicrystalline silicon by using the iron precipitate size distribution obtained from crystal growth simulations as initial condition for gettering. [Copyright &y& Elsevier]

Abstract: Competitive gettering of iron was studied in silicon wafers with internal gettering sites in the bulk and implanted boron region near the wafer surface. The experimental results indicate that iron precipitation in the implanted boron region is significant. We show that internal gettering can reduce precipitated iron concentration in the heavily boron doped device layer but the optimization of internal gettering is a challenging task as typically precipitation (nucleation) is faster in heavily boron doped region. We also perform simulations to support the experimental results. Simulation results were found to be in accordance with the experimental results. [Copyright &y& Elsevier]

Abstract: Density-functional theory is used to model interstitial iron and its complexes with aluminum in Si-rich SiGe alloys with Ge concentration up to 8%. Both short-range and long-range defect-Ge interactions are considered. It is found that Fe prefers Si-rich regions. The shifts of the electrical levels of Fe-acceptor pairs are calculated using the marker method. [Copyright &y& Elsevier]

Abstract: The gettering during an emitter diffusion in multicrystalline silicon is improved by adding a low-temperature tail to the standard diffusion. The tail keeps the emitter sheet resistance within the usable range for solar cells. An increase in minority carrier lifetime by a factor ten is obtained. Decrease in recombination activity of grain boundaries and decrease in interstitial iron concentration are mainly responsible for this improved lifetime. The proposed mechanisms for this improvement are: reduction of size of precipitates because of the longer duration, possibly assisted by beneficial changes in thermodynamics and kinetics of the gettering because of the low temperature. [Copyright &y& Elsevier]

Abstract: Gettering behaviors of Fe into solar cell grade Si are investigated by deep level transient spectroscopy. The samples contaminated with Fe in the range of the concentration of 1.5×1012–2.0×1014 cm−3 were annealed at 600°C to induce gettering. It is shown that the surface layer gettering behaviors of Fe for the sample without p+ layer strongly depend on the Fe contamination level, in which the surface layer gettering is not effective for the sample with low level contamination <1×1013 cm−3 but effective for the sample with middle level contamination of 1–5×1013 cm−3. In contrast, the samples with p+ layer show effective gettering for low and middle level contaminations. The gettering mechanisms in solar cell grade Si without and with p+ layer are discussed in details. [Copyright &y& Elsevier]

Polysilicon/oxide (poly-Si/SiO x) passivating contacts are a promising technology for the next-generation of high-efficiency silicon solar cells. The structure can be realised by a range of fabrication techniques, which can induce very different impurity gettering effects during the formation process. Understanding the different gettering effects will enable tailored solutions to optimise the gettering efficiency in device fabrication. This paper demonstrates a method to separately quantify the impact of each component on the overall gettering effect of the poly-Si/SiO x passivating contact structures. These components consist of the heavily doped poly-Si layer, in terms of its gettering strength; the SiO x interlayer, regarding its potential blocking effect for slowing down the diffusion of impurities; and the dopant in-diffused surface regions of the silicon wafer bulk directly below the SiO x interlayer, which may have a small additional gettering effect due to heavy doping. Phosphorus in-situ doped poly-Si layers from plasma-enhanced chemical vapour deposition (PECVD), coupled with SiO x interlayers from different growth techniques, were used to demonstrate the method. The experimental and simulation results confirm that the heavily doped poly-Si layer acts as the main gettering sink and the presence of different SiO x interlayers determines the overall gettering rate. For the ultrathin SiO x interlayers studied in this work, which have a similar thickness but different stoichiometry, a standard thermally grown SiO x demonstrates the strongest blocking effect, followed by a chemically grown SiO x from hot nitric acid, and a thermal SiO x of a reduced stoichiometry (grown in a pure nitrogen ambient) demonstrates practically no blocking effect. • A method to separate and quantify the impact of each component on the overall gettering effect of polysilicon/oxide. • Component 1: Heavily doped polysilicon layer, the main gettering sink. • Component 2: Ultrathin silicon oxide interlayer, a diffusion barrier that slows down the overall gettering rate. • Component 3: In-diffused crystalline silicon surface region, which may have a small gettering effect due to heavy doping. • PECVD in-situ P-doped polysilicon layers, with various oxide interlayers, are used to demonstrate the method. • Different blocking effects of the oxide interlayers can be quantified through fitting experimental kinetics by simulation. • Experimental gettering results after a typical structure formation process can be well reproduced by simulation. [ABSTRACT FROM AUTHOR]