LAUSR

In this paper, the etching characteristics of the ultra-high resistivity silicon (UHRS) by using the Bosch process were investigated. The experimental results indicated that the sulfur hexafluoride flux, the temperature of the substrate, the platen power and the etching intermittence had important influence on the etching rate and the etching morphology of the UHRS. The profiles and morphologies of sidewall were characterized with scanning electron microscopy (SEM). By using an improved three-stage Bosch process, 380- μ m deep through holes were fabricated on the UHRS with the average etching rate of about 3.14 μ m/min. Meanwhile, the fabrication mechanism of deep through holes on the UHRS by using the three-stage Bosch process was illustrated on the basis of the experimental results.