延伸波长InGaAs红外焦平面低失调电压读出电路研究

发布时间：2019-02-23 20:11

【摘要】：延伸波长In Ga As红外焦平面在航天遥感、军事和民用领域有着广泛应用。截止波长为2.5μm的延伸波长In Ga As光敏芯片由于其晶格失配,相同温度下暗电流比响应波长为1.7μm的晶格匹配In Ga As光敏芯片高几个数量级,降低延伸波长In Ga As红外探测器的暗电流成为实际应用中亟待解决的问题。优化In Ga As材料和器件工艺可有效降低光敏芯片暗电流,由于探测器的暗电流和偏置电压密切相关,降低耦合接口处光敏芯片的偏置电压也可以减小光敏芯片的暗电流。本文从红外焦平面读出电路的角度出发,研究通过降低耦合接口偏置电压实现降低焦平面暗电流的设计方法。首先介绍了延伸波长In Ga As红外焦平面发展现状及趋势;讨论了几种类型的红外焦平面耦合接口,针对具有暗电流和背景电流抑制功能的电路进行了调研和比较;运用Monte Carlo方法仿真了运放失调电压和各MOS管尺寸的关系,并讨论了小像元面阵红外焦平面低失调电压耦合结构的设计方法;针对线列读出电路提出了一种新型Autozero结构的CTIA输入级的设计方法,在负反馈回路中运用了一种双电源CMOS反相器,消除了开关漏电流的影响,耦合接口失调电压仿真结果达到23μV。测试结果表明,电路与截止波长为1.7μm的红外探测器耦合后,可将暗电流降低至10f A数量级,比反偏10m V时实测暗电流降低一个数量级;电路与截止波长为2.5μm的红外探测器耦合后,用杜瓦封装,在180K、200K、220K、240K条件下测试,暗电流均比反偏10m V时实测暗电流降低一个数量级。
[Abstract]:Extended wavelength In Ga As infrared focal plane is widely used in space remote sensing, military and civil fields. Due to the lattice mismatch of the extended wavelength In Ga As-Guang Min chip with a cutoff wavelength of 2.5 渭 m, the dark current at the same temperature is several orders of magnitude higher than that of the lattice-matched In Ga As Guang Min chip with a response wavelength of 1.7 渭 m. Reducing the dark current of the extended wavelength In Ga As infrared detector has become an urgent problem in practical application. Optimizing the technology of In Ga As materials and devices can effectively reduce the dark current of Guang Min chip. Because the dark current of the detector is closely related to the bias voltage, the bias voltage of Guang Min chip at the coupling interface can also reduce the dark current of Guang Min chip. From the point of view of infrared focal plane readout circuit, this paper studies the design method of reducing the dark current of focal plane by reducing the bias voltage of the coupling interface. Firstly, the development status and trend of extended wavelength In Ga As infrared focal plane are introduced, and several kinds of infrared focal plane coupling interfaces are discussed, and the circuits with dark current and background current suppression are investigated and compared. The Monte Carlo method is used to simulate the relationship between the offset voltage of operational amplifier and the size of each MOS tube, and the design method of the low offset voltage coupling structure of the small pixel array infrared focal plane is discussed. A new design method of CTIA input stage based on Autozero structure is proposed for linear readout circuits. A double power CMOS inverter is used in the negative feedback loop, which eliminates the influence of the leakage current of the switch. The simulation results of the offset voltage of the coupling interface reach 23 渭 V. The test results show that the dark current can be reduced to the order of 10f A by coupling the circuit with an infrared detector with a cut-off wavelength of 1.7 m, which is one order of magnitude lower than the measured dark current at an inverse deviation of 10 MV. When the circuit is coupled with the infrared detector with a cut-off wavelength of 2.5 渭 m, the dark current is reduced by one order of magnitude compared with the measured dark current at reverse bias of 10 MV, and is encapsulated by Dewar and tested at 180K / 200KN / 220KN 240K.
【学位授予单位】：中国科学院研究生院(上海技术物理研究所)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN219

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