应用于蓝宝石直接键合的减薄抛光工艺

Thinning and Polishing Technology for Sapphire Direct Bonding

蓝宝石晶片的总厚度差（TTV）和表面粗糙度是影响蓝宝石键合成败的关键因素。研究了减薄抛光工艺对蓝宝石衬底的作用机理,结合实际加工要求选择不同粒径磨料组合和适当的压力条件对蓝宝石晶片进行减薄。之后对减薄后的蓝宝石晶片进行抛光,通过控制抛光液流速、抛光盘转速、抛光压力得到了低TTV、低表面粗糙度的蓝宝石晶片。采用测厚仪测量了减薄前后蓝宝石晶片五点不同位置的厚度,得到了其TTV值;采用原子力显微镜（AFM）得到抛光后晶片表面粗糙度,并且研究了不同工艺条件对减薄抛光速率的影响。最后通过蓝宝石直接键合验证了减薄抛光工艺参数的合理性。

The total thickness variation（TTV）and surface roughness of the sapphire wafer are the key factors affecting the success or failure of sapphire bonding.The effect mechanism of the thinning and polishing process on the sapphire substrate was studied.The sapphire wafers were thinned according to the actual processing requirements by choosing abrasive combinations with different particle sizes and appropriate pressure conditions.Then the thinned sapphire wafer was polished by controlling the flow rate of the polishing solution,the polishing pad speed and the polishing pressure to obtain the sapphire wafer with low TTV and low surface roughness.The thicknesses of five positions on the sapphire wafer before and after thinning were measured by the thickness gauge,and the TTV value was obtained.The surface roughness of the polished wafer was obtained by the atomic force microscope（AFM）.The effects of different processing conditions on the thinning and polishing rate were also studied.Finally,the reasonability of thinning and polishing process parameters was verified by the direct bonding of the sapphire.