InP单晶片翘曲度控制技术研究

Study on Reducing the Warp of InP Wafer

InP单晶片受热场及机械损伤的作用而产生翘曲形变,这种形变在外延过程中会产生滑移线,也会影响外延层厚度均匀性,最终影响外延质量,因此必须采取措施对InP衬底的翘曲度加以控制。切割工艺是影响晶片翘曲度的关键,但受InP单晶特性及切割工艺自身的限制,InP切片的翘曲度仍保持在一个较高的水平,不能满足高质量外延的要求,需要采取措施进一步降低翘曲度。讨论了用化学腐蚀方法降低InP单晶切片翘曲度,研究了化学腐蚀液的组分、温度及腐蚀去除量对InP单晶片翘曲度的影响,综合工艺的稳定性和实际操作的便利性及晶片翘曲度的实际测试结果,确定了降低InP单晶片翘曲度的适宜工艺。

The warp of InP wafers is due to the growth condition of the crystal and the mechanical damage of the wafers. The mechanical damage can be reduced by chemical method. The effect of the etching process parameters, such as the solution proportion, temperature and etching removal, is researched. The results indicate that the warp of InP wafers change with the etching rate, which is effected by the solution proportion and temperature. The higher the etching rate is, the lower the warp of InP wafers is. However, the warp of InP wafers reduce with the etching removal only at certain range. The warp of InP wafers is reduced remarkably when the etching solution is proportion C, the solution temperature is at 50℃ and the etching removal is about 5 μm.