背照式像素电学串扰及其抑制

为改善背照式像素电学串扰问题，建立了小尺寸背面照射像素间的串扰物理模型，提出了一种应用于背照式像素的防串扰结构。该结构基于正面照射像素隔离原理，在相邻像素间器件层背面插入沟槽隔离区域。仿真结果显示，短波串扰构成了背照式像素中最为严重的串扰源；相邻像素经该结构优化后，可有效隔离背表面中短波串扰电荷；当沟槽深为3μm时，相邻像素串扰量可由32．73％降至8．76％；当沟槽深为4μm时，相邻像素可实现电学串扰的完全抑制。此外，量子效率也会因该结构的使用而得到相应改善。

Electrical crosstalk and elimination for 4T back-side illuminated pixei

In order to tackle the serious electrical crosstalk problems in the backside illuminated （t38I） pixel, a crosstalk physical model based on BSI pixel was established to study low crosstalk optimization method. Based on the front-side isolation principles, the back-side trench isolation （BTI） was proposed. The backside of adjacent pixels was etched and isolated by a trench isolation region, and the lateral diffusion charges could be directly and effectively isolated, decreasing the shortwave crosstalk efficiently. Simulation results show that the main source of crosstalk comes from the short and middle wavelength. When the trench groove depth is 3 tim, the crosstalk could be effectively reduced from 32.73~ to 8. 760//oo. When the trench groove depth is 4 tim, the e lectrical crosstalk between adjacent pixels could get total elimination. Adopting this particular structure could not only eliminate electrical crosstalk but also improve the quantum efficiency for the small size BSI.