Improvement of on-pixel polarizer with 0.35 μm CMOS process for electro-optic imaging systems. (1st April 2023)

• Record Type: Journal Article
• Authors: Okada, Ryoma; Sasagawa, Kiyotaka; Mizuno, Maya; Takehara, Hironari; Haruta, Makito; Tashiro, Hiroyuki; Ohta, Jun
• Is Part Of: Japanese journal of applied physics. Volume 62:Number SC(2023)
• Publication Date: 2023-04-01
• Subjects: CMOS image sensor -- porarization image sensor -- electric-field imaging -- on-chip polarizer -- electro-optic imaging; Physics -- Periodicals; 621.05
• DOI: 10.35848/1347-4065/acb0da
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: In this paper, we propose an improved on-pixel polarizer structure for an image sensor, which was fabricated using the 0.35 μ m standard CMOS process with dual metal layers (Metal 1 and Metal 2), i.e. two layers of gratings with metal-wiring layers were stacked. By designing the line/space ratio as 0.7/0.7 μ m, the extinction ratio was significantly improved at a wavelength of 780 nm, which was over 1.4 times higher than that of a single-layer grating, and the detection sensitivity of the polarization change was enhanced by more than 1.8 times. We also demonstrated electro-optical imaging at radio frequency using this image sensor.