Method for manufacturing silicon substrate having silicon oxide film
By patterning deep trenches and thermally oxidizing silicon substrates, the method addresses the challenges of forming thick silicon oxide films with high quality and reduced processing time, achieving films with improved stress resistance and optical properties.
WO2026146557A1PCT designated stage Publication Date: 2026-07-09
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Filing Date
- 2024-12-31
- Publication Date
- 2026-07-09
Smart Images
Figure JP2024046507_09072026_PF_FP_ABST
Abstract
[Problem] To provide a method for manufacturing with remarkable speed a silicon substrate having a thick silicon oxide film with a thickness of at least 2 μm and excellent film properties, e.g. hardness, refractive index, and optical transmittance, with low internal stress resulting in reduced warpage and deformation. [Solution] The method includes: a first step of patterning an etching mask for deep trenches on a surface of a silicon substrate; a second step of forming deep trenches in the silicon substrate by using deep reactive ion etching (D-RIE); and a third step of forming a thick silicon oxide film by oxidizing the surface of the silicon substrate in which the deep trenches are formed by a thermal oxidation method, oxidizing all silicon of ridges defined by the deep trenches, and filling the deep trenches with volume-expanding silicon oxide.
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