Preparation of Uniform SiO2 Insulating Layer on the Inner Wall of TSV by Thermal Oxidation

SiO
2
insulating layer is an indispensable part of a TSV. In the current process, the SiO
2
insulating layer is commonly deposited on the inner wall of the TSV based on deep trench sputtering method. The thickness at different position (neck, middle, bottom) of the SiO
2
insulating layer, deposited by deep trench sputtering, is non-uniform. In this paper, the thickness uniformity of SiO
2
insulating layer prepared on the inner wall of TSV based on CVD&PVD process and thermal oxidation method is comparatively studied. The experimental results show that, based on the CVD&PVD process, the average thickness of the SiO
2
insulating layer at middle and bottom position of the TSV has changed by - 54.02% and - 58.30% compared with that at the top position, respectively. Based on the thermal oxidation method, the average thickness of the SiO
2
insulating layer at middle and bottom position of the TSV has changed by 1.17% and 0.26% compared with that at the top position, respectively. The thermal oxidation method can realize the SiO
2
insulating layer with uniform thickness on the inner wall of TSV.