6.4 mm Diameter silicon micromachined lens for THz dielectric antenna

In this paper, we have microfabricated a 6.4 mm diameter silicon lens array on a 4 inch silicon wafer using silicon micromachining technique. The goal of this lens array is to build a 2×2 lens antenna array for 1.9 THz receiver application. It requires multiple thick photoresist coatings and long selective etching of silicon and photoresist after thermal reflow process. To the authors´ knowledge, this is the biggest silicon lens ever microfabricated by semiconductor process.