TCAD-ASSISTED TECHNIQUE FOR DETERMINING THE PARAMETERS OF MICROLENSES USED IN PHOTOSENSITIVE CCD VLSI

In this paper we introduce the simulation technique for photosensitive cell with CCD VLSI microlens with interline transfer. A microlens enhances the photosensitivity of the cell and reduces image blur. The technique is based on the calculation and comparison of the volumetric photogeneration rate integrals of different areas of the photocell, where generated charge carriers are collected and transferred. This technique does not require simulation of the full frame accumulation cycle of the cell, significantly reducing the time of simulation and enabling the evaluation of many design options for microlenses. The technique is implemented in the Sentaurus TCAD (by Synopsys). In the paper we present the results of simulation made for cells with various microlenses. The proposed technique can also be used for the optimization of microlenses of CMOS photodiode VLSI photocells.

The Influence of the Magnetic Field on the Current-Voltage Characteristics of CuPc Nanowires

The role of spin states in the process of charge carrier transport in copper phthalocyanine (CuPc) nanowires has been established. According to the data obtained, CuPc nanowires are in the η-phase. The current-voltage characteristics (IVC) of a photosensitive cell based on CuPc nanowires in a magnetic field are investigated. As a result of experiments, it was found that applying an external magnetic field, the spins of two positively charged polarons are oriented in one direction. The channel of formation of the bipolaron is blocked. As a result, a decrease in the short-circuit current of the photosensitive cell is observed by more than 61%.

High Spatial Resolution Three-Dimensional Imaging Static Unitary Detector-Based Laser Detection and Ranging Sensor

This paper presents a static unitary detector (STUD)-based laser detection and ranging (LADAR) sensor with a 16-to-1 transimpedance-combining amplifier for high spatial resolution three-dimensional (3-D) applications. In order to readout the large size of a photodetector for better results of 3-D information without any reduction of the bandwidth, the partitioning photosensitive cell method is embedded in a 16-to-1 transimpedance-combining amplifier. The effective number of partitioning photosensitive cells and signal-combining stages are selected based on the analysis of the partitioning photosensitive cell method for the optimum performance of a transimpedance-combining amplifier. A prototype chip is fabricated in a 0.18-μm CMOS technology. The input referred noise is 41.9 pA/√Hz with a bandwidth of 230 MHz and a transimpedance gain of 70.4 dB·Ω. The total power consumption of the prototype chip is approximately 86 mW from a 1.8-V supply, and the TICA consumes approximately 15.4 mW of it.

Sensitivity of CCD matrices with electronic multiplication

The sensitivity and basic electrical characteristics of the developed direct illumination matrices with charge-coupled devices and electronic multiplication were investigated at room temperatures and low illumination. Photomatrices of 576´288 and 640´512 format were designed using frame transfer architecture and 1.5-µm design rules with photosensitive cell sizes of 20´30 and 16´16 µm, respectively, and manufactured using n-channel technology with buried channel, four levels of polysilicon electrodes and two levels of metallization. To analyze the possibilities of the developed EMCCD matrices used in monitoring systems at low-light conditions, an experimental assessment of the matrices sensitivity was carried out. The assessment was based on a comparison of the luxmeter readings and Johnson's criteria using the standard 1951 USAF resolution target test table for the minimum size of line pairs distinguished by the observer (one pair consists of a dark and a light lines). The characteristics obtained with illumination of 5∙10–4 lux (glow of the starry sky with light clouds) and 10–2 lux (glow of the starry sky and the quarter of the Moon) corresponds to the parameters of generation 2+ electron-optical converters, which implies the possibility to use such matrices in night vision devices. At Åv ≈ 5∙10–4 lux, the camera with the developed EMCCD matrices will detect a human figure at the distance of about 200 m. With illumination of 10–2 lux at this distance a human figure can be identified.

CCD Imagers by Enhanced UV Sensitivity for Industrial and Scientific Applications

A family of virtual phase (VP) CCD array image sensors for various industrial and scientific applications has been designed, fabricated and tested. All share the common concept of a “2.5-phase” photosensitive cell, combining the advantages of known “1.5-phase” VP devices (increased quantum efficiency, especially in the UV, and radiation hardness) with the simpler fabrication process and extended functionality of three-phase devices.