Abstract

A device is described that allows one to measure the photosensitivity contrast over the area of n⁺–p(n)–p⁺ silicon structures without contacts. The structure is placed between the capacitor plates and is locally illuminated on one side by two intensity-modulated lasers. The laser wavelengths are 1064 and 808 nm. The radiations of the first and second lasers are absorbed in the volume of the base region and only near its illuminated surface, respectively. The local photosensitivity is determined by the ratio of the amplitudes of the modulations, at which the total variable photo-emf vanishes. This compensation allows one to avoid an error that is associated with shunting of the illuminated area of the structure by the rest of it due to currents in the n⁺ and p⁺ layers. The photosensitivity contrasts measured by the proposed compensation method and the standard method based on short-circuit current measurements were compared on n⁺–p–p⁺ single-crystal silicon structures. The difference was no more than 6%, which is consistent with the calculations.

中文翻译：

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非接触测定n + – p（n）– p +型硅结构区域光敏度分布的装置

摘要

描述了一种设备，该设备可以测量n ⁺ – p（n）– p ⁺区域上的光敏对比度。无触点的硅结构。该结构放置在电容器极板之间，并在一侧通过两个强度调制的激光器进行局部照明。激光波长为1064和808 nm。第一和第二激光的辐射分别在基本区域的体积中并且仅在其受照表面附近被吸收。局部光敏性由调制幅度的比例决定，总可变光电动势在该比例上消失。这种补偿可以避免由于n ⁺和p ^+中的电流而导致的与结构的照明区域被其余部分分流有关的误差。层。在n ⁺ – p – p ⁺单晶硅结构上，比较了建议的补偿方法和基于短路电流测量的标准方法测量的光敏对比度。差异不超过6％，与计算结果一致。