用于空间硅像素X射线探测器的低噪声与抗辐射读出芯片研制

Recently, the particle detector spectrometers in astronomy research satellites and space station have used Application Specific Integrated Circuits (ASICs) in their electronic readout system more often, which is an inevitable result of the combination of astronomical experimental requirements and electronics development. There is little study about this kind of ASIC in China, indeed there is no very suitable solution in the developed lab abroad for our plans. This causes great difficulties to the design for scientific experiment system used in astronomy satellites. . This project focuses on the study of readout ASIC to match silicon pixel detector used in some astronomy satellites or space station. Try to design a chip with characteristics of good universality, low noise and radiation-hardening.The function of this ASIC is converting the detector pulse signal to DC voltage signal which stand for the particle energy and moment of arriving, and outputing them to ADC serially.This ASIC contains 32 channels. For each channel, signal which is preprocessed by a low-noise preamplifier is sent to the slow-shaper to form a quasi-Gaussian pulse and keep its peak for readout; at the same time, the signal is sent to the fast-shaper for timing information. . By this research, we can not only get chips which can be used in space astronomy research, but also master design and testing methods for multi-channel readout ASIC for particle detectors, especially for parameter of low noise and radiation-hardening. The structure of the ASIC is widely applicable. It can meet the demands of many other kinds of particle detectors for data readout.

近年来，天文科研卫星或空间站中X射线探测器已开始使用专用集成电路芯片，这是天文实验要求与集成电子学发展相结合的必然结果。国内甚至国外在此类芯片设计领域尚无成熟的方案，这成为天文科学实验系统设计的瓶颈。本项目主要针对硅像素探测器读出电路进行研究，拟设计出一款功能完善、在低噪声与抗辐射性能上达到国际先进水平的芯片。芯片将探测器脉冲信号转换成代表粒子能量及时间信息的电平信号，并串行输出。共32个通道，每通道采用的方案是：低噪声前置放大器对信号进行预处理，然后分别送入滤波成形电路形成准高斯型脉冲，保持峰值供读出；同时送入快成形电路得到时间信息供读出。该项目完成后，可得到芯片供多类天文卫星或空间站相关探测器使用；还能掌握多通道粒子探测器读出芯片设计方法，掌握低噪声、抗辐射集成电路设计测试方法，为更多核电子学芯片设计提供参考。本芯片有广泛的应用前景，稍加改动可满足多种粒子探测器的前端数据读出需要。

近年来，天文科研卫星或空间站中X射线探测器已开始使用专用集成电路读出芯片，这是天文实验要求与集成电子学发展相结合的必然结果。国内甚至国外在此类芯片设计领域尚无成熟的方案，这成为天文科学实验系统设计的瓶颈。本项目主要针对硅探测器读出进行研究，设计出一款功能完善、在低噪声与抗辐射性能上达到国际先进水平的芯片。主要研究了CMOS（互补金属氧化物半导体）工艺下，半导体X射线探测器的低噪声读出技术，包含容性探测器噪声匹配，低寄生电容组装，低电容、低漏电静电保护技术等；以及配套的成形，峰值保持，稀疏读取读出技术及低噪声读出系统。同时，也研究了CMOS工艺芯片的单粒子辐射效应和总剂量辐射效应及其加固技术，并设计了辐射效应测试系统进行实际测试。本项目设计的读出芯片实测等效输入噪声能达到20个等效噪声电子，远优于51个电子的预设目标。实测单粒子辐射锁定阈值达到56.7MeV*cm2/mg以上，也超过目标规定的37MeV*cm2/mg的阈值。设计了32通道完整芯片，将于2020年末得到最终结果。本项目已发表多篇论文，获得专利授权，培养数名研究生，部分芯片已在国内空间项目中试用。本项目总结出的半导体X射线探测器CMOS工艺读出芯片的低噪声设计方法及抗辐射设计方法，可推广到其它同类芯片设计中。本项目填补了国内此类芯片的空白，打破了国外禁运，能大大提高我国空间科学中此类实验装置的性能及国际竞争力。