Open AccessRoom-temperature bonded silicon on insulator wafers with a dense buried oxide layer formed by annealing a deposited silicon oxidation layer and surface-activated bonding
Author(s) -
Yoshio Koga,
Kazunari Kurita
Publication year - 2021
Publication title -
japanese journal of applied physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 129
eISSN - 1347-4065
pISSN - 0021-4922
DOI - 10.35848/1347-4065/abe2b9
Subject(s) - silicon on insulator , materials science , wafer , annealing (glass) , fabrication , wafer bonding , silicon , microelectromechanical systems , thermal oxidation , layer (electronics) , optoelectronics , oxide , chemical vapor deposition , anodic bonding , composite material , nanotechnology , metallurgy , medicine , alternative medicine , pathology
We propose a fabrication process for a silicon on insulator (SOI) wafer with an extremely thick buried oxide (BOX) layer for custom micro-electro mechanical systems (MEMS) devices. A BOX layer is generally formed by thermal oxidation above 800 °C. It is limited for this method to form an extremely thick layer of more than 10 μ m. Thus, we attempted to deposit the BOX layer by chemical vapor deposition at 300 °C for a short time, followed by annealing at above 300 °C to make it denser. In addition, a silicon layer was bonded to the BOX layer at room temperature by surface activated bonding not to receive thermal stress. As a result, the bonding interface had no voids. The breakdown electric field of the BOX layer in the accidental B mode was improved by annealing. Therefore, SOI wafers fabricated by our method will be beneficial to next-generation MEMS device fabrication.