垂直多结PPD像素势阱容量与电荷转移研究

研究了一种具有垂直多结结构的CMOS图像传感器四管像素结构,通过引入垂直多结结构可扩展感光区的势阱容量,增大耗尽区,提高信号电荷收集效率,特别对于长波长光波的吸收大幅增加。并为减小垂直多结结构的图像拖影现象,在N区水平方向上进行梯度掺杂,消除了电位障,使得信号电荷更易向外传输,从而减小图像拖影现象,并通过SILVACO TCAD软件对该结构进行数值仿真。

Full Well Capacity And Charge Transfer Study for PPD Pixel With Vertical Multi-Junction Structure

An 4-T CMOS image sensor pixel with vertical multi-junction structure was investigated.By introducing vertical multi-junction structure can extend the full well capacity of the photosensitive area,the depletion region is increased to improve the collection efficiency of signal charge,especially for long wavelength light absorption greatly increased.And,to reduce the image lag of vertical multi-junction structure,a horizontal gradient doping eliminating the potential barrier,thus,the signal charge easier to pass out,reducing image lag.Its performance was verified by simulation with SILVACO TCAD software.