适用于低应力氮化硅薄膜的LPCVD设备

LPCVD Equipment for Low Stress Silicon Nitride Thin Films

针对适用于低应力氮化硅薄膜淀积的低压化学气相沉积(LPCVD)工艺中出现的薄膜应力大、应力均匀性差、工艺颗粒超标的问题,设计开发出一种适用于半导体器件的低应力立式LPCVD设备。在结构上,工艺腔采用双管式结构,内管为直筒式结构,以提高气流场均匀性;增加舟旋转功能,以提高晶圆表面的气体浓度一致性;在工艺设计上,验证并确定最佳的DCS(二氯二氢硅)与NH3气体流量比例,以及温度和真空度。通过工艺优化及验证,得到应力低于200 MPa的薄膜的淀积工艺。

According to the Problems such as high film stress,poor stress uniformity,and excessive process particles that occurred in the process of LPCVD which is applied to the low stress silicon nitride thin fi lm deposition,a low stress vertical LPCVD device suitable for semiconductor devices is designed and developed.Structurally,in order to improve the uniformity of the flow field,the process chamber adopts double tube structure,and the inner tube is straight tube structure.In order to improve the consistency of gas concentration on the wafer surface,the rotation function of boat is added.In process design,the best DCS and NH3 gas fl ow ratio,temperature and vacuum degree are verifi ed and determined.Through process optimization and verifi cation,the fi lm deposition process with stress below 200 MPa is obtained.