Search

Integrated circuits based on wide bandgap semiconductors are considered an attractive option for meeting the demand for high-temperature electronics. Here, we report an analog-to-digital converter fabricated in a silicon carbide complementary metal-oxide-semiconductor technology now available through Europractice. The MOSFET component in this technology was measured up to 500 °C, and the key parameters, such as threshold voltage, field-effect mobility, and channel-length modulation parameters, were extracted. A 4-bit flash data converter, consisting of 266 transistors, is implemented with this technology and demonstrates correct operation up to 400 °C. Finally, the gate oxide quality is investigated by time-dependent dielectric breakdown measurements at 500 °C. A field-acceleration factor of 4.4 dec/(MV/cm) is obtained by applying the E model., Electronic Components, Technology and Materials, Microelectronics

In this work, a highly linear temperature sensor based on a silicon carbide (SiC) p-n diode is presented. Under a constant current biasing, the diode has an excellent linear response to the temperature (from room temperature to 600°C). The best linearity (coefficient of determination ${R}^{{2}}$ = 99.98%) is achieved when the current density is 0.53 mA/cm2. The maximum sensitivity of the p-n diode is 3.04 mV/°C. The temperature sensor is fully compatible with Fraunhofer Institute (FHG) IISB's open SiC CMOS (complementary metal-oxide-semiconductor) technology, thus enabling the monolithic integration with SiC readout circuits for high-temperature applications. The sensor also features a simple fabrication process. To our knowledge, the presented device is the first SiC diode temperature sensor that does not require a mesa etch or backside contacts., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Electrical Engineering, Mathematics and Computer Science, Electronic Components, Technology and Materials

The next generation of satellites will need to tackle tomorrow's challenges for communication, navigation and observation. In order to do so, it is expected that the amount of satellites in orbit will keep increasing, form smart constellations and miniaturize individual satellites to make access to space cost effective. To enable this next generation of activities in space, it is vital to ensure the ability of these satellites to properly navigate themselves. This control starts with attitude measurement by the dedicated sensors on the satellite, commonly performed by sun position sensors. The state-of-the art is confronted by large signal distortions caused by light reflected by the Earth's albedo as well as keeping up with the satellite miniaturization trend. This work aims to address both these issues, by presenting a microfabricated albedo insensitive sun position sensor in silicon carbide with wafer-level integrated optics. The presented 10 mm×10 mm×1 mm system reaches a mean angular accuracy of 5.7° in a ±37° field-of-view and integrates an on-chip temperature sensor with a -3.9 mV K−1 sensitivity in the 20 °C to 200 °C range., Microelectronics, Electronic Components, Technology and Materials

This work presents the design and characterization of an analog-to-digital converter (ADC) with silicon carbide (SiC) for sensing applications in harsh environments. The SiC-based ADC is implemented with the state-of-the-art low-voltage SiC complementary-metal-oxide-semiconductor (CMOS) technology developed by Fraunhofer IISB. Two types of ADCs, i.e., a 4-bit flash ADC and a 6-bit successive-approximation (SAR) ADC, are designed and simulated up to 300 degrees Celsius. The measurement results show that the 4-bit SiC flash ADC can operate reliably up to at least 200 degrees Celsius, which outperforms the Si counterpart regarding the maximum operating temperature., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Electronic Components, Technology and Materials, Microelectronics

The wide bandgap of silicon carbide (SiC) has attracted a large interest over the past years in many research fields, such as power electronics, high operation temperature circuits, harsh environmental sensing, and more. To facilitate research on complex integrated SiC circuits, ensure reproducibility, and cut down cost, the availability of a low-voltage SiC technology for integrated circuits is of paramount importance. Here, we report on a scalable and open state-of-the-art SiC CMOS technology that addresses this need. An overview of technology parameters, including MOSFET threshold voltage, subthreshold slope, slope factor, and process transconductance, is reported. Conventional integrated digital and analog circuits, ranging from inverters to a 2-bit analog-to-digital converter, are reported. First yield predictions for both analog and digital circuits show great potential for increasing the amount of integrated devices in future applications., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Electronic Components, Technology and Materials

The continuous trend to integrate more multi-functions in a package often involves, Heterogeneous Integration of multi-functional blocks in some kind of 3D stacking. The conventional flip chip for die-on-substrate technology applies solder for integration. However, solder joint integration has the disadvantages of restricting height, reflow issues and re-melting at high operating temperatures. Nanometallic particle sintering offers a potential solution for these solder related issues. Nanometallic particle sintering occurs at low temperature and does not reflow and melt at higher temperatures. Hence, it can be applied for quite precise alignment and integration technologies, such as photonic components on silicon for harsh environment applications. In order to test this concept, we use sapphire and Si wafers with different mechanical properties, which can lead to the coefficient of thermal expansion mismatch. The sapphire chip can operate at a higher temperature applied for ultraviolet photonics application. This report describes a novel approach using copper nanoparticles paste patterned through photolithographic stencil printing. The photoresist acts as the stencil mask, and a photoresist lift-off process is applied to strip the photoresist stencil. This process has the advantages of lithographic form factor and precision and provides a chip to chip interconnect with a standard height of 20 µm., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Electronic Components, Technology and Materials, Microelectronics

In this work, a novel microfabrication-compatible production process is demonstrated and used to fabricate UV photoresistors made from ZnO nanoparticles. It comprises a simple room-temperature production method for synthesizing and direct-writing nanoparticles. The method can be used on a wide range of surfaces and print a wide range of materials. Here, it is used to synthesize a ZnO photoresistor for the first time. The sensor shows a two orders of magnitude lower resistance under UV-C exposure compared to darkness. The low cost and simplicity of this synthesis method enables cheap integration of UV-C sensors for human exposure monitoring or UV-output monitoring of light sources., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Electronic Components, Technology and Materials, Microelectronics

An angle sensitive optical sensor without conventional optics is presented in this article. The reported device omits the need for adding 3-D optics in postprocessing by monolithic integration of complimentary metal-oxide semiconductor compatible diffraction grating layers, which cuts down the fabrication costs and allows for miniaturization of these types of sensors. The sensor resolves angular information from a monochromatic light source over a single axis with a mean absolute accuracy of 0.6° in an investigated $\pm 26$° field-of-view using four unique pixels. This letter facilitates miniaturization of light source trackers, such as sun position sensors on small satellites of the future., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Electronic Components, Technology and Materials

In this paper, we present a quadrant sun position sensor microsystem device in a silicon carbide technology that operates in a field-of-view of ±33° and reaches a mean error of 1.9° in this range. This will allow, for the first time, an inherently visible blind sun position sensor in a CMOS compatible technology. Opto-electronic integration of the photodetectors and CMOS readout circuitry on-chip is vital to compete with the performance of silicon state-of-the-art and for the concept to be adopted by industry, which is where previous implementations of visible blind sun sensors are lacking., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Electronic Components, Technology and Materials

The growing diversity in the used materials in semiconductor packaging provides challenges for achieving good interconnection. Particularly the very soft substrates, such as paper and polymers, and very hard, such as silicon carbide, offer unique challenges to wire-bonding or formation of vertical interconnects. Complementary technologies are therefore needed. Here, a method to direct-write metal tracks on the top and sides of dies is demonstrated. It is based on a spark ablation aerosol printing process entirely performed at room temperature and without any applied force. Therefore, it is suitable for use on soft or temperature-sensitive substrates. The printed metal lines consist of pure Au nanoparticles, without surfactants or contaminants, and do not require any further curing, cleaning, or other processing. The process is demonstrated on Si dies and paper, but is theoretically applicable on a wide variety of substrate materials. It can provide an alternative method to create interconnects or vias on soft materials, temperature sensitive materials, irregularly shaped materials, or curved surfaces., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Electronic Components, Technology and Materials

In this paper we present a sun position sensor platform with a scalable approach for the 3D integration of the sensor optics. This would facilitate the sun position sensor miniaturization, reduces fabrication cost and mitigates the need for sensor calibration. The sun position sensor platform is implemented in a seven mask BICMOS technology with optical windows between the light masking layer and CMOS image sensor implemented by adhesively bonded glass windows. The CMOS sensor functionality is experimentally verified by modulation of a light spot using a laser. The proposed approach enables wafer-scale fabrication of the 3D optics that includes the wafer stepper accurate overlay alignment of the apertures. This mitigates the need for cumbersome alignment of the apertures at die or package level and facilitates further miniaturization, accuracy and sensor cost., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care, Electronic Components, Technology and Materials

The operating principle of Pirani pressure sensors is based on the pressure dependence of a suspended strip's electrical conductivity, caused by the thermal conductance of the surrounding gas which changes the Joule heating of the strip. To realize such sensors, not only materials with high temperature dependent electrical conductivity are required, but also minimization of the suspended strip dimensions is essential to maximize the responsivity and minimize the power consumption. Due to this, nanomaterials are especially attractive for this application. Here, we demonstrate the use of a multi-layer suspended graphene strip as a Pirani pressure sensor and compare its behavior with existing models. A clear pressure dependence of the strip's electrical resistance is observed, with a maximum relative change of 2.75% between 1 and 1000 mbar and a power consumption of 8.5 mW. The use of graphene enables miniaturization of the device footprint by 100 times compared to state-of-the-art. Moreover, miniaturization allows for lower power consumption and/or higher responsivity and the sensor's nanogap enables operation near atmospheric pressure that can be used in applications such as barometers for altitude measurement. Furthermore, we demonstrate that the sensor response depends on the type of gas molecules, which opens up the way to selective gas sensing applications. Finally, the graphene synthesis technology is compatible with wafer-scale fabrication, potentially enabling future chip-level integration with readout electronics., Electronic Components, Technology and Materials, Photovoltaic Materials and Devices, QN/van der Zant Lab, Dynamics of Micro and Nano Systems, QN/Steeneken Lab

Accurately sensing the temperature in silicon carbide (power) devices is of great importance to their reliable operation. Here, temperature sensors by resistive and CMOS structures are fabricated and characterized in an open silicon carbide CMOS technology. Over a range of 25-200°C, doped design layers have negative temperature coefficients of resistance, with a maximum change of 79%. Secondly, CMOS devices are used to implement a CTAT, which achieves a maximum sensitivity of 7.5mV/K in a temperature range of 25-165°C. The integration of readout electronics and sensors that are capable of operation in higher temperature than silicon, opens application in harsher environments., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Electronic Components, Technology and Materials