CMOS compatible MEMS pyroelectric infrared detectors: from AlN to ScAlN

We present the optical and electrical properties of AlN-based and 12% doped ScAlN-based pyroelectric detectors fabricated on 8-inch wafers respectively. Both AlN and ScAlN materials are deposited at a temperature of similar to 200 degrees C, making them potential candidates for CMOS compatible MEMS pyroelectric detectors. FTIR spectroscopy is used to measure the absorption of these pyroelectric detectors over the wavelength range of similar to 2-14 mu m and the results show absorption improvement up to similar to 75% for ScAlN-based pyroelectric detectors compared to that of AlN-based pyroelectric detectors at the wavelength of 4.26 mu m where CO2 gas absorption of IR radiation is anticipated. Higher output current (similar to 3-fold increase) is also observed from ScA1N based pyroelectric detectors. Other than pyroelectric coefficient that contributes to improved performance for ScAlN-based pyroelectric detectors, we believe that absorptivity of the device also plays a major role in the performance of pyroelectric IR detectors. The results obtained from the study of the electrical and optical properties of AlN-based and ScAlN-based CMOS compatible MEMS pyroelectric detectors will bring forth potential applications of these detectors onto multi-functional integrable and monolithic platforms.

Automated summary

The optical and electrical properties of AlN-based and ScAlN-based pyroelectric detectors on 8-inch wafers were analyzed. ScAlN-based detectors showed higher absorption improvement and output current, indicating potential applications in multi-functional integrable and monolithic platforms.