Sharon Bar-Lev

Measurements and Simulations of Low Dark Count Rate Single Photon Avalanche Diode Device in a Low Voltage 180-nm CMOS Image Sensor Technology

This paper presents the key features of single photon avalanche diode (SPAD) devices fabricated in a low voltage commercial 180-nm CMOS image sensor technology exhibiting very low dark count rate (DCR). The measured DCR is <; 100 Hz at room temperature even for excess voltages above 2 V. The active junction of the SPAD measures 10 μm in diameter within a 24-μm test structure. The active region where Geiger avalanche occurs is determined by an implanted charge sheet. Edge avalanche is averted by utilizing a virtual guard ring, formed by the retrograde well profile. The design, measurements, and simulations of doping and electric field profiles that lead to such low DCR are reported and analyzed. The current-voltage characteristics and the temperature dependence of the breakdown voltage provide further, indirect evidence for the low DCR measured in the device. Thus, the key features of measured good SPADs are presented and are correlated with simulations that give physical insight on how to design high-performance SPADs.

CMOS-SOI-MEMS Transistor for Uncooled IR Imaging

This paper reports the design, fabrication technology, post-CMOS micromachining and characterization of CMOS-silicon-on-insulator (SOI)-microelectromechanical system (MEMS) transistors. The thermally isolated micromachined CMOS-SOI-MEMS transistor reported here is designed for uncooled infrared (IR) sensing and is dubbed here as ldquoTMOS.rdquo The measured dc and noise electrical characteristics of the as-processed (virgin) transistor as well as those of the post-CMOS-MEMS-processed transistor (TMOS) are reported and compared. In particular, the threshold voltage temperature dependence and the temperature coefficient of current (TCC) at subthreshold are reported. The results indicate that the post-CMOS-MEMS processing does not degrade the performance of the transistors. The electrooptical performance of the TMOS is characterized and reported. With TCC on the order of 4%-10%, depending on the gate voltage, responsivity of 40 mA/W, noise equivalent power on the order of several tens of picowatts, and calculated noise equivalent temperature difference on the order of 64 mK, this uncooled IR sensor in standard CMOS-SOI technology may provide a high performance at a lower cost compared to state-of-the-art uncooled sensors based on bolometers implemented in non-CMOS materials like vanadium oxide or amorphous silicon.

Characterization of a novel micromachined accelerometer with enhanced-MIDOS

This paper reports the successful realization of a novel micromachined accelerometer with a highly sensitive in-plane optical motion sensor. Two arrays of CMOS integrated photodiodes are used to detect the motion of a matching micromachined suspended grid. Sub-angstrom displacements of the suspended grid are detected by the integrated readout electronics that amplify and subtract the resulting photocurrents from each array. The device is fabricated by deep reactive ion etching (DRIE) and then flip-chip bonded on the CMOS chip. A preliminary prototype with a natural frequency of 2500[Hz] exhibited a noise equivalent acceleration (NEA) of /spl sim/40[/spl mu/g//spl radic/(Hz)] and a dynamic range >90[dB] with linearity <0.1%.

The TeraMOS sensing pixel for monolithic passive uncooled THz imagers

We report a novel THz sensor, based on several leading technologies: THz photonics, CMOS-SOI and NEMS. By integrating the TeraMOS sensor with “thermal antenna”, we expect to achieve a breakthrough in uncooled Terahertz passive imaging.

Modeling of CMOS-SOI-MEMS Thermal Antenna for Monolithic Passive Uncooled THz Imagers

We present modeling and simulations of uncooled passive THz imaging sensor based on a thermal antenna. The 2D CMOS-SOI-MEMS imager pixel array constitutes a frequency selective surface tuned to the desired wavelength band.

CMOS-SOI-MEMS transistor (TMOS) for infrared imaging

The novel concept of thermally isolated CMOS-SOI-MEMS transistor serving as IR detector (TMOS) is presented and characterized, showing high potential for thermal imaging, allowing long integration time because of negligible self heating.

TMOS novel uncooled sensors — theory and practice

This paper presents a novel approach, where the sensor is implemented as MOS transistor on SOI wafer, and is used as uncooled thermal detector (TMOS). The sensor is operated in subthreshold region where the current has exponential dependence on temperature with current sensitivities exceeding 4%/K. The fabrication of the sensor using standard and reliable CMOS-SOI technology combined with monolithic integration of readout circuitry and very simple post-processing, guaranties low production cost and predicts high performance.

CMOS-SOI-NEMS uncooled infrared presence sensor

Previous reports of various IEEE conferences have described a new generation of uncooled passive infrared (PIR) security sensors based on a suspended transistor (TMOS) fabricated in standard CMOS-SOI process and released by post-etching. The patented technology is now under development for commercial applications. This study focuses on the design and performance of a small sensing array, known as a presence sensor, which is required for the detection of people in smart homes and has a wide range of applications in smart homes. The spatial resolution of this technology demonstrator is limited because of the relatively small number of pixels, but the thermal performance is excellent, with pixel NETD of ∼20mK. For the complete system with readout the evaluated NETD is ∼35mK. Based on standard technology and outstanding performance of high sensitivity and ultralow power consumptions, this presence sensor has a huge potential for commercial applications.

Modeling of CMOS-SOI-MEMS thermal antenna for monolithic passive uncooled THz imagers

We present electromagnetic, thermal, electrical, and mechanical modeling and simulations of uncooled passive THz imaging sensor based on a thermal antenna. The 2-D CMOS-SOI-MEMS imager pixel array constitutes a frequency selective surface tuned to the desired wavelength band. The modeling predicts enhanced performance of the symmetric design in terms of electromagnetic absorption, mechanical planarity, thermal response, and electrical signal.

High performance integrated inductors for power management applications

We report here a study on integrated in-package inductors with and without ferrite core for monolithic DC2DC buck converter. The power IC is designed and fabricated with standard 0.18 μm CMOS process and the inductor is fabricated with CMOS 0.18 μm three layers process. Prototype high power (0.6-1.2W) converter in package (SiP) is designed to operate at ~10MHz with optional configuration for higher frequencies.