IGBT全自对准栅挖槽工艺研究

A Process Technology for Fully Self-Aligned Trench-Gate IGBT's

设计了一种全自对准槽栅IGBT(绝缘栅双极晶体管)结构,其工艺简单,全套工艺只有两张光刻版,提高了工艺成品率。它独特的IGBT沟道多重短路结构,有效地防止了器件闩锁;采用氧化层硬掩膜和硅化物工艺,实现了全自对准的多晶硅反刻和金属连接,增加了IGBT芯片单位面积的元胞密度和沟道宽度,提高了器件的电流能力;用砷(As)掺杂代替磷(P)掺杂,有效地提高了源区表面浓度,实现了浅结工艺。

A simplified process technology for fully self-aligned trench-gate IGBT's (Insulated Gate Bipolar Transistors) is designed, in which only two masks are needed and no alignment is required between the two masks, thus eliminating the alignment error and increase the process yields. A unique multi-channel short-circuit structure is designed to effectively suppress latch-up of the IGBT. Polysilicon etching back is self-aligned with the pre-oxide layer as a hard mask. so increases the packing density and channel width per chip area, improving the current capability of the device. Using As, instead of P, as source doping, the surface concentration in the source region is effectively increased when shallow junction structure is employed.