A functional CMOS compatible MEMS pyroelectric detector using 12%-doped scandium aluminum nitride
Doris K. T. Ng, Tan‐Tan Zhang, Li Yan Siow, Xu Liang, Chong Pei Ho, Hong Cai, Lennon Y. T. Lee, Q. Zhang, Navab Singh
Abstract
In this paper, we fabricate and demonstrate a functional complementary metal-oxide-semiconductor (CMOS) compatible pyroelectric uncooled thermal detector using 12% doped Scandium Aluminum Nitride (ScAlN) as the sensing layer. The ScAlN pyroelectric material is deposited at a temperature of ∼200 °C over an 8-in. wafer area. This detector has shown, in general, improved performance compared to AlN, with specific detectivity as high as ∼ 6.08×107 cm Hz/W and noise equivalent power as low as ∼ 8.85×10−10 W/Hz. The results show the specific detectivity of ScAlN-based pyroelectric detectors in the range of 107 cm Hz/W, which is an improvement compared to AlN-based pyroelectric detectors which report specific detectivity typically in the range of 105–106 cm Hz/W. This promising result opens up the opportunities for a CMOS compatible, 8-in. wafer-level manufacturable lead-free pyroelectric detector toward low cost and high throughput, allowing microelectromechanical systems (MEMS) and CMOS integration for increased applications in CMOS–MEMS integrated devices utilizing pyroelectric detectors.