Uncooled IR Nanobolometers Fabricated by Electron Beam Lithography and a MEMS/CMOS Process

We combine electron beam lithography (EBL) with conventional microscale metal deposition and etch process technologies, to fabricate bolometer devices with nanoscale feature critical dimensions (CDs). We report the creation of titanium (Ti) bolometer devices with 70 nm minimum feature CDs, and total bolometer film thicknesses ranging between 40 nm and 120 nm. Our new nanobolometer devices integrate with conventional CMOS and MEMS fabrication processing, to create thermally isolated sensors with nanoscale feature sizes on a 0.5 mum CMOS base process. We present temperature coefficient of resistance (TCR) data for our new devices, and report a nanobolometer TCR performance of 0.22%/K at 70 nm CDs, a TCR value comparable to figures reported for Ti-based uncooled microbolometer devices.