High-bandwidth CMOS APD device

Abstract

The invention requests to protect a high-bandwidth CMOS APD device, a conventional CMOS APD structure does not consider a bandwidth improvement method except a depletion layer, and only considers reduction of transverse and longitudinal widths of the depletion layer to reduce minority carrier transit time. In order to further improve the bandwidth of the CMOS APD, therefore, the length L from theelectrode to the boundary of the N+ layer of the illumination region and the electrode area are adjusted to increase. Under the condition of avalanche multiplication, for a P+/N well type CMOS APD, the hole lateral carrier transit distance is reduced by adjusting the distance L between a cathode electrode on N+ and the boundary and the size of the electrode, and then the carrier transit time is prolonged; and, for the P+/N well type CMOS APD, the hole lateral electron carrier transit distance is reduced by adjusting the distance L between the anode electrode on the P+ and the boundary and theelectrode size, so that the carrier transit time is prolonged, and the bandwidth is increased. According to the improved technology, the electrode distance and the electrode area size are improved, carriers are reduced, and the bandwidth is increased.

Description

technical field [0001] The invention belongs to the technical field of visible light detection, and in particular relates to a high-bandwidth CMOS APD device. Background technique [0002] Avalanche Photodiode (Avalanche Photodiode) is a photodetector capable of high sensitivity and high bandwidth. It has electrons, holes that are multiplied by absorbing the optical signal in the depletion layer by utilizing avalanche breakdown. The basic design technology of CMOS APD is similar to the basic design technology of ordinary PN junction, but the new design technology is adopted in the design process, which can effectively improve the working bandwidth of the device. CMOS APDs operating in the linear region are widely used in the Internet of Things, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) and Blu-ray disc due to its low voltage and low cost. [0003] The device design technology of CMOS APD can be divided into two categories according to the type of...

AI Technical Summary

Problems solved by technology

The traditional APD device design technology is only optimized on the P+ / N well, ignoring the reasonable use of the horizontal and vertical crossing distance of photogenerated electron carriers, so it cannot achieve high bandwidth while maintaining a small size

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