In high-temperature pressure sensors, the E-type diaphragm offers advantages such as strong stability,minimal nonlinear error, and higher sensitivity under the same deflection compared to the C-type diaphragm.The preparation of thin films is crucial in the MEMS process, given that their morphology and structure greatly influencesensor performance. However, there are several challenges in preparing E-type thin films. To produce Etype(silicon island) thin films with good morphology, a DRIE deep reactive ion etching machine was used with SF6as the main etching gas. The preparation process was optimized and improved using changing the mask material,and the morphology after etching was characterized using confocal microscopy and scanning electron microscopy(SEM). Experiments showed that using ROL-7133 negative adhesive and a SiO2 double mask, with pre-drying for90 s, mid-drying for 120 s, and developing for 50 s, resulted in E-type films with a silicon island height of 50 μmand a back cavity depth of 450 μm. These films exhibited high perpendicularity and good overall morphology, meetingthe requirements for sensor production.