GaN基紫外探测器读出电路注入效率

读出电路的注入效率是决定紫外焦平面探测器性能的重要因素。基于GaN基p-i-n结构日盲紫外探测器以及CTIA结构读出电路的等效模型，对探测器信号读出的电荷注入效率进行了分析，得到了注入效率的表达式。分析了注入效率与积分时间、探测器等效电阻、探测器等效结电容、CTIA电路中运算放大器增益的依赖关系，并指出了放大器增益是有效影响注入效率的重要可控因素之一，可以用提高增益的方法获得更大的注入效率。设计了几种不同增益的运算放大器电路，并分别构成CTIA结构读出电路。采用GF 0.35 m 2P4M标准CMOS工艺设计电路版图并进行流片。将紫外探测器分别连接至具有不同放大器增益的CTIA读出电路并进行测试，通过对比注入效率的理论分析结果与实际测试结果，可以得知，注入效率的理论分析与实验结果吻合较好。

Injection efficiency of GaN based ultraviolet detector readout circuit

The injection efficiency of the readout circuit is an important factor that determines the performance of ultraviolet(UV) focal plane array detectors. Based on the equivalent model of the gallium nitride(GaN) based p-i-n structure solar blind UV detector and the capacitor feedback transimpendance amplifier(CTIA) readout circuit, the injection efficiency of photo-generated carrier of the detector was analyzed, then the expression of injection efficiency was obtained. The relationship among injection efficiency and integration time, the equivalent resistor and capacitor of UV detector, the gain of amplifier in CTIA was analyzed. The result indicates the gain of amplifier in CTIA is one of the crucial importance controllable factor that can affect the injection efficiency. Meanwhile, higher injection efficiency can be obtained by improving the gain of amplifier in CTIA. Several amplifiers with different gain were presented, and the CTIA structure readout circuits were made up by using these different amplifiers. A chip was designed and fabricated by using 0.35 m 2P4M mixed signal CMOS process. The ultraviolet detector was individually connected to the CTIA readout circuit with different amplifier gain and the test was carried out. Then the theoretical analysis result of injection efficiency was compared with the testing results. It indicates that the theoretical analysis of injection efficiency agrees well with the actual experimental test result.