电子倍增电荷耦合器件中多针相工作模式

Multi Pinned Phase Mode in Electron Multiplying Charge Coupled Devices

针对微光条件下,电子倍增电荷耦合器件(EMCCD)的暗电流噪声将会随信号一起在倍增寄存器中放大,信号仍会湮没于噪声中。该文提出将多针相(MPP)模式引入EMCCD,通过在栅极上加较大的负偏压,使得空穴填充Si-SiO2界面态,抑制电子的跃迁和传导,以减小暗电流的产生率。研究结果表明,T=300 K时,MPP模式下EMCCD的暗电流值为0.021 3 nA/cm2,而非MPP模式下EMCCD表面暗电流稳态值为1.79 nA/cm2。说明MPP模式的引入极大地降低了EMCCD的暗电流水平,同时提高了整个微光成像系统的探测灵敏度和信噪比。

In the low light level condition, the dark current noise is enlarged with the signal in the multiplying registers of electron multiplying charge coupled devices （EMCCDs） , and the signal is lost in the dark current. To solve the problem, a multi pinned phase （MPP） mode is introduced into the EMCCD. With the negative bias applied on the gates, the silicon-silicon dioxide interface is populated by holes, the hopping conduction process is suppressed, and the dark current generation rate is much reduced. The results show that, when temperature is 300 K, the dark current of EMCCD is 0. 021 3 nA/cm^2 in MPP mode operation and 1.79 nA/cm^2 in non-MPP mode. Dark current is evidently curtailed by the introdution of the MPP mode into the EMCCD. The detecting sensitivity and signal to noise ratio of low light level imaging system is also significantly improved.