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Multi-omic approaches are promising a broader view on cellular processes and a deeper understanding of biological systems. with strongly improved high-throughput methods the amounts of data generated have become huge, and their handling challenging. Area Covered: New bioinformatic tools and pipelines for the integration of data from different omics disciplines continue to emerge, and will support scientists to reliably interpret data in the context of biological processes. comprehensive data integration strategies will fundamentally improve systems biology and systems medicine. to present recent developments of integrative omics, the göttingen proteomics forum (gpf) organized its 6th symposium on the 23rd of november 2017, as part of a series of regular gpf symposia. more than 140 scientists attended the event that highlighted the challenges and opportunities but also the caveats of integrating data from different omics disciplines. Expert commentary: The continuous exponential growth in omics data require similar development in software solutions for handling this challenge. Integrative omics tools offer the chance to handle this challenge but profound investigations and coordinated efforts are required to boost this field.

Advances in Bioanalytical Mass Spectrometry: 5th Symposium of the Gottingen Proteomics Forum Mass Spectrometry with Spatial Resolution: MALDI-Imaging and Laser Capture Microscopy Gottingen, Germany, 22 November 2012 MALDI mass spectrometry imaging (MSI) combines the speed and molecular specificity of MALDI-MS detection with information on spatial organization. In the last years, MSI found large application in proteomics research for determining the spatial distribution of compounds in biological tissues and started to draw increasing interest in clinical research. To shed light on the new developments in the field of MSI, the Gottingen Proteomics Forum organized a symposium that was held in Gottingen as part of the series of regular symposia organized by the members of the Gottingen Proteomics Forum. The symposium was on 22 November 2012, with more than 80 delegates that attended the event entitled 'Mass spectrometry with spatial resolution: MALDI-imaging and laser capture microscopy'. The one-day agenda consisted of nine oral presentations from renowned experts in the field with subsequent discussion sessions. As usual, the meeting was fruitful and offered a good platform for discussion between the delegates and proteomics specialists.

Semiconductor devices, which utilize the interaction between photons and semiconductors, are applied as photosensors for various ranges of photon energy, photovoltaic cells, sensors in electrophotography, image sensors, etc. For CCD devices cf. Chapter 14, p. 201; for photovoltaic (solar) cells cf. Chapter 32, p. 321.

General. Patterned silicon nitride layers are used as masks for growing epitaxial compound semiconductor layers, as masks for doping by diffusion or ion implantation, and as protective dielectric layers in fabricating LEDs.

Semiconductor substrates or devices are encapsulated with high temperature-resistant silicon nitride films to protect them against damage caused by high-temperature processes. These include diffusion, electrical activation of implanted dopants, and annealing of radiation damage caused by ion implantation. Silicon nitride encapsulation prevents the decomposition of a semiconductor substrate and the diffusion or evaporation of species at elevated process temperatures. The major application of silicon nitride films as an encapsulant involves compound semiconductors and, to a minor extent, element semiconductors.

In insulating silicon nitride films, the dielectrical properties of silicon nitride are of primary importance, whereas in encapsulating and passivating silicon nitride films, the chemical barrier properties are utilized. Of course, the same film can serve more than one application. Some work on insulating silicon nitride films that is not directly related to a particular device is presented in this chapter.

Capacitors can be used for charge storage, for example, in one-transistor/one-capacitor dynamic memory cells of ICs. Silicon nitride is used as a dielectric to separate the two electrodes of the capacitor, one of them usually being the semiconductor substrate, the second one a top layer of a conductive material. Silicon nitride masks are also used to define the capacitor area during device processing

The problem to grow natural, insulating oxides with good properties on compound semiconductors such as GaAs does not favor the fabrication and application of bipolar devices and even less of MIS devices. Therefore, silicon nitride plays an important role as a masking material for diffusion, implantation, and as dielectric in the manufacture of compound semiconductor devices.

Silicon nitride is widely known for its application in integrated circuit technology as encapsulation material, as interlevel insulator for multilevel metallization, as gate dielectric for field effect transistors including memory devices, as a mask for oxidation, diffusion or ion implantation, for selective etching, and as a capping layer for compound semiconductors. Most of these applications are due to the fact that silicon nitride is an excellent diffusion barrier and a gettering and passivating agent regardless how the films are prepared, whether by atmospheric pressure (APCVD), low pressure (LPCVD), or plasma-enhanced (PECVD) chemical vapor deposition, by sputtering, or by electron-beam evaporation, only to mention a few preparation techniques [1 to 3]. PECVD silicon nitride, in the literature often also just named “plasma” silicon nitride, is in many cases just labeled “pd(PD)” silicon nitride throughout this Chapter 32.

Silicon nitride is used in the manufacture of bipolar devices, such as diodes, transistors, power transistors, and thyristors, mainly as an auxiliary means, e.g., as masking material in the different processing steps. As a basic functional constituent, silicon nitride is less used in bipolar device technology than in MISFET technology.

Devices, transistors, and ICs fabricated in thin surface layers of semiconductor wafers can have parasitic leakage currents into the bulk of the semiconductor substrate. These effects can be eliminated if the devices in thin semiconductor films are manufactured on insulating substrates, such as sapphire (SOS), spinel, or more generally on insulators (SOI), such as silicon nitride.

The principle applications of thin silicon nitride layers are for gate dielectrics and processing masks in field effect devices, such as MESFETs, JFETs, IGFETs, MISFETs, and subfamilies, such as MOSFETs, MNSFETs, MNOSFETs, etc., of which ICs are composed. The use of silicon nitride in MIS, MNS, and MNOS devices is reviewed in [1 to 3].

Integrated circuits (ICs) based on bipolar devices may be faster than ICs based on field effect devices. However, bipolar circuits exhibit some restrictions in obtaining high integration densities due to isolation problems, parasitic capacitances, and high power consumption. Inactive regions are much larger than the active ones.

Charge-coupled devices (CCD) are applied to integrate circuits for signal processing, optical imaging, and computer memory. The device consists of an input element for injecting a controlled charge into the main part, an array of MIS capacitors used in the dynamic operation mode, and a sensor device registering the charge arriving at the end of the array. Charge losses must be minimized. This imposes severe requirements on the quality of the gate insulator.

Monolithic device elements and devices have to be well-isolated from each other to avoid performance-limiting interactions or cross talk. Unwanted interactions due to electric contact or carrier tunneling are prevented by dielectric layers of silicon nitride which are thick enough to insulate. Grooves, which separate device components and devices, are etched into the silicon nitride or silicon nitride/silicon oxide layers and into the substrate. Bird’s beak has to be suppressed to obtain high integration density. The finished devices have to have a smooth surface to avoid interconnection problems.

Silicon nitride is applied in the field of high-temperature superconductors as a buffer layer between the substrate and a superconducting film, as encapsulant during annealing, and as a top layer mainly for passivating against humidity and to obtain longterm stability.

Point defects and certain types of impurities cause leakage currents and reduce the carrier lifetime. They are observed as secondary effects in high-temperature diffusion and oxidation processes. These defects and impurities can be gettered or trapped in lattice damage sites acting as sinks, thus avoiding deleterious device degradation. Gettering is performed at elevated temperatures.

Patterned or unpatterned silicon nitride films are used as masks in structured or unstructured, epitaxial or amorphous growth of semiconductor layers on single-crystal or amorphous substrates. The silicon nitride mask is stable compared to the conventionally used silicon oxide mask. Amorphous silicon nitride films are a constituent element of superlattice structures which are base materials for novel devices.

The field of sensors provides special applications for silicon nitride. Sensors are used, e.g., to monitor parameters, specifically in biochemistry and medicine, controlling processes and process conditions, and ensuring safety in manufacturing. In the following, they will be grouped into particle-sensitive or “chemical” sensors and nonparticle-sensitive or “physical” sensors.

One of the crucial components in FET-based ICs is the thin dielectric layer which insulates the active portion of the device from the gate. Suitable silicon nitride layers are formed by thermal nitridation of Si, which due to the diffusion barrier effect is limited to a silicon nitride thickness less than 6 nm, and by plasma nitridation in dry NH3 up to a thickness of 20 nm [1], by ion implantation of nitrogen [2], plasma deposition, or nitridation of silicon oxide to form nitride oxide layers with a variable nitrogen content of up to 50 at%.

Silicon nitride is applied in integrated optics, for example, in coupling active and passive optical components, such as monolithically integrated devices, which convert electric signals into photons, and complementary ones, which convert photons into electric signals. Topics concerning optical materials, such as epitaxial growth of silicon nitride and its mechanism, were reported [1].

Semiconductor devices have to be stable and long-lasting. Electronically active parts of such devices are often thin surface layers with a thickness as low as 20 nm. p-n junctions that emerge at the surface are sensitive to mechanical damage, moisture, contamination, chemical attack, radiation, etc. Devices are protected or passivated by applying thin silicon nitride surface layers which become an integral part of the basic device and secure its specified function for a predetermined minimum period of time [1, 2]. Passivation prevents surface leakage, high diffusivity, and mobility of impurities, such as Na or K, and reduces localized near-surface states. For the determination of passivation effects, see for example [4]. The application of protective silicon nitride layers in special high-temperature processes is described in Chapter 7.1, p. 99. See also the introductory remarks of Chapter 4, p. 72.

There are two types of masks for manufacturing device structures by lithographic methods on substrates.

Silicon nitride is applied in monolithic, integrated, digital, and analog circuits composed of FETs, diodes, resistors, and thin-film capacitors on compound semiconductor substrates. Silicon nitride can be used as a mask for implanting Si to produce n-type layers and for implanting hydrogen to achieve isolation by generating radiation damage. It can also be used for encapsulating before annealing, providing recessed Mo-Au gates, and for passivation [1,2]. ICs on GaAs with a high degree of integration are fabricated by the same technique by preparing patterned multilayers consisting of a silicon nitride layer sandwiched with a silicon oxide and a PSG layer prior to annealing and preparing contacts and gate contacts [3]. Highspeed, ion-implanted GaAs ICs are annealed using a silicon nitride oxide layer for encapsulation. The silicon nitride oxide layer is deposited in a mixture of SiH4, NH3, and 02 at 923 K. The subsequent annealing is performed at 1073 K [4]. Alternatively, GaAs specimens are coated with a silicon nitride oxide layer, patterned, implanted with silicon ions, encapsulated with a silicon nitride layer, and annealed to prepare high-speed GaAs ICs [5].

The read-only memories (ROMs) are ICs where stored information is expected not to be changed during operation. Such memories have breakdown voltages much higher than the normal operating voltages. This offers the possibility to program finished ROMs after installing them in the equipment as needed applying higher voltages. Sub-classes of the general family of programmable memories, the PROMs, are the nonvolatile, electrically programmable, and UV-light erasable ROMs (EPROMs), the electrically programmable and electrically erasable ROMs (EEPROMs), to which also the so-called floating gate avalanche injection MOS (FAMOS) and electrically alterable ROMs (EAROMs) can be added.

There are applications of silicon nitride which were not covered in the preceding chapters. Some of those will be briefly mentioned here. Others to be touched upon serve to indicate the diversity of applications for silicon nitride films.

This chapter gives the results on miscellaneous magnetic materials as their fabrication involves application of silicon nitride.

Contacts are monolithic, usually heterogeneous, connecting links between active and peripheral, inactive interconnections of a device. Contacts and interconnections can be prepared simultaneously in the same process step. The contacts and the different interconnecting systems are provided with a reliable electric insulation of silicon nitride. Silicon nitride may also be used as masking material in fabricating contacts and interconnections.

Resistors may consist of semiconducting stripes of one type conductivity with contact pads on both ends, monolithically integrated in a semiconductor substrate of the opposite type conductivity. Masks of patterned silicon nitride layers are used to produce resistors by selective diffusion or ion implantation.

The chemistry of preparing silicon nitride and the techniques to fabricate thin layers of silicon nitride in general are covered in detail in “Silicon” Suppl. Vol. B 5a. Preparation techniques relevant to general applications of silicon nitride in microelectronics are treated briefly in Chapter 2.1, p. 5; those relevant to specific devices are included in the respective chapters of this volume.

Advanced processing of integrated circuits in bipolar and MOS technology becomes more and more identical. The design even merges both types of elements (BiMOS technique) making use of the inherent advantages of both the bipolar and MIS techniques. Silicon nitride masks are used for selective oxidation in IC fabrication including bipolar and FET devices, i.e. at least one bipolar transistor and at least one insulated-gate FET [1]; for their use in deposition and patterning of polycrystalline Si, see [2]. See also [3, 4] for use as dielectric, n-p-n bipolar transistors and n-channel MOS transistors are prepared in the BiMOS IC technique using nitride masks for selective oxidation to form the field oxide and for implanting boron ions to form the base region [5]. The current transport (holes or electrons) in such MNOS structures with complementary, tunneling emitter, bipolar transistors has been studied [6].

Random access memories (RAMs) are memories where information can be written in during operation and, vice versa, information can be read out. The conventional static memory cell (SRAM) consists of two inverters and six transistors designed in NMOS or CMOS technology. Dynamic RAM (DRAM) cells contain only a single transistor.

PPh4[UBr6] und PPh4[UBr6] · 2CCl4 wurden aus UBr5 · CH3CN und Tetraphenylphosphonium-bromid in Dichlormethan erhalten, letzteres nach Zusatz von CCl4. Ihre Kristallstrukturen wurden durch Rontgenbeugung aufgeklart. PPh4[UBr6]: 2101 beobachtete Reflexe, R = 9,0%, Raumgruppe C2/c, Z = 4, a = 2315,5, b = 695,0, c = 1805,2 pm, β = 96,38°. PPh4[UBr6] · 2CCl4: 2973 Reflexe, R = 7,4%, Raumgruppe P21/c, Z = 4, a = 1111,5, b = 2114,2, c = 1718,7 pm, β = 95,42°. Uranpentabromid wird durch Schwefelwasserstoff zu Urantetrabromid reduziert. Losungen von UBr5 mit 1 bzw. mehr als 3 Molaquivalenten Acetonitril in Dichlormethan spalten beim Eindampfen Brom ab, dabei entsteht UBr4 · CH3CN bzw. UBr4 · 3CH3CN. Diese reagieren in Acetonitril mit PPh4Br unter Bildung von (PPh4)2[UBr6] · 4CH3CN, dessen Kristallstruktur bestimmt wurde (2663 beobachtete Reflexe, R = 5,0%): Raumgruppe P21/c, Z = 2, a = 981,8, b = 2010,1, c = 1549,3 pm, β = 98,79°. Die Reduktion von Uranpentabromid mit Tetramethylammonium-hydrogensulfid in Dibrommethan fuhrt zu (NEt4)2[U2Br10], das extrem hydrolyse- und sauerstoffempfindlich ist. Ebenso empfindlich ist (PPh4)2[U2Br10], das aus UBr4 und PPh4Br in CH2Cl2 erhalten wurde. Von seinem Oxidationsprodukt (PPh4)2[UO2Br4] · 2CH2Cl2 wurde die Kristallstruktur bestimmt (2163 Reflexe, R = 8,3%): Raumgruppe C2/c, Z = 4, a = 2006,3, b = 1320,6, c = 2042,5 pm, β = 98,78°. Die UBr-Bindungslangen in den oktaedrischen Anionen be tragen im Mittel 266,2 pm beim UBr6−, 276,7 pm beim UBr62− und 282,5 beim UO2Br42−. Reactions of Uranium Pentabromide. Crystal Structures of PPh4[UBr6], PPh4[UBr6] · 2CCl4, (PPh4)2[UBr6] · 4CH3CN, and (PPh4)2[UO2Br4] · 2CH2Cl2 PPh4[UBr6] and PPh4[UBr6] · 2CCl4 were obtained from UBr5 · CH3CN and tetraphenylphosphonium bromide in dichloromethane, the latter being precipitated by CCl4. Their crystal structures were determined by X-ray diffraction. PPh4[UBr6]: 2101 observed reflexions, R = 0.090, space group C2/c, Z = 4, a = 2315.5, b = 695.0, c = 1805.2 pm, β = 96.38°. PPh4[UBr6] · 2CCl4: 2973 reflexions, R = 0.074, space group P21/c, Z = 4, a = 1111.5, b = 2114.2, c = 1718.7 pm, β = 95.42°. Hydrogen sulfide reduces uranium pentabromide to uranium tetrabromide. Upon evaporation, bromide is evolved from solutions of UBr5 with 1 or more then 3 mol equivalents of acetonitrile in dichlormethane yielding UBr4 · CH3CN and UBr4 · 3CH3CN, respectively. These react with PPh4Br in acetonitrile affording (PPh4)2[UBr6] · 4CH3CN, the crystal structure of which was determined: 2663 reflexions, R = 0.050, space group P21/c, Z = 2, a = 981.8, b = 2010.1, c = 1549.3 pm, β = 98.79°. By reduction of uranium pentabromide with tetraethylammonium hydrogen sulfide in dichloromethane (NEt4)2[U2Br10] was obtained; (PPh4)2[U2Br10] formed from UBr4 and PPh4Br in CH2Cl2. Both compounds are extremely sensitive towards moisture and oxygen. The crystal structure of the oxydation product of the latter compound, (PPh4)2[U02Br4]· 2 CH2Cl2, was determined: 2163 reflexions, R = 0.083, space group C2/c, Z = 4, a = 2006.3, b = 1320.6, c = 2042,5 pm, β = 98.78°. Mean values for the UBr bond lengths in the octahedral anions are 266.2 pm for UBr6-, 276.7 pm for UBr62− and 282.5 pm for UO2Br42−