Improved Specific Detectivity to 107 for CMOS-MEMS Pyroelectric Detector Based on 12%-Doped Scandium Aluminum Nitride

CMOS-MEMS pyroelectric detectors based on 12%-doped ScAlN are fabricated using 8-inch MEMS wafer technology and characterized. The ScAlN pyroelectric material is deposited at a low temperature of ~200
^o
C. The results show D* as high as 4.3 x 10
⁷
(cm√Hz)/W and NEP as low as 1.26 x 10
^-9
W/√Hz. This is the first demonstration of a functional CMOS-MEMS pyroelectric detector using ScAlN as the pyroelectric sensing material. Compared to AlN that usually presents D* in the range of 10
⁵
-10
⁶
, Sc-doped AlN brings on the promise of better performing CMOS-MEMS pyroelectric detectors that could be miniaturized, integrated with CMOS circuits and provide wider applications.