A Review of 3-Dimensional Wafer Level Stacked Backside Illuminated CMOS Image Sensor Process Technologies

2022 June

Authors Shou-Gwo Wuu, Hsin-Li Chen, Ho-Ching Chien, Paul Enquist*, R. Michael Guidash**, John McCarten***
*Semasense LLC
**R. M. Guidash Consulting LLC

IEEE Transactions on Electron Devices

Over the past 10 years, 3-dimensional (3-D) wafer-level stacked backside Illuminated (BSI) CMOS image sensors (CISs) have undergone rapid progress in development and performance and are now in mass production. This review paper covers the key processes and technology components of 3-D integrated BSI devices, as well as results from early devices fabricated and tested in 2007 and 2008. This article is divided into three main sections. Section II covers wafer-level bonding technology. Section III covers the key wafer fabrication process modules for BSI 3-D wafer-level stacking. Section IV presents the device results.