为了避免深沟槽隔离过程中出现缝隙,提出了一种有利于多晶硅回填的倒梯形沟槽。这种沟槽的开口处宽度比底部宽度大,使用了一种优化的微机械加工工艺,利用各向同性刻蚀形成了一种倒梯形沟槽。另一方面,对于填充效果而言,完全光滑过渡的曲线型沟槽好于具有尖锐转角的曲线型沟槽。相比于直线型沟槽,完全光滑过渡的曲线型沟槽可以提高机械连接强度。通过使用新的沟槽设计以及优化的微机械工艺,可以获得无缝隙的深沟槽,最终实现了一种无缝隙的沟槽隔离,保证了两个可动结构之间或一个可动结构和一个固定结构之间的电绝缘。 In order to avoid the occurrence of cracks in the deep trench isolation process, an inverted trapezoidal trench is proposed to facilitate the backfilling of polysilicon. The trenches are wider at the opening than at the bottom, using an optimized micromachining process that uses isotropic etching to create an inverted trapezoidal groove. On the other hand, for the filling effect, the curved groove of a completely smooth transition is better than the curved groove of sharp corners. Compared with the straight groove, a completely smooth transition of the curved groove can improve the mechanical connection strength. By using the new trench design and optimized micromachining technology, it is possible to obtain a seamless deep trench, resulting in a seamless trench isolation, ensuring that two movable structures or a movable structure and a Electrical insulation between fixed structures.