ガラスファイバ円筒面より漏洩する光を援用したエッチングによる輪郭転写加工

Abstract

Light-assisted etching is a processing method that enables selective etching by light illumination onto semiconductors in an etchant. In this study, we propose the cylindrical surface forming technique by light-assisting etching using leaking light from cylindrical glass fibers. When a light propagating glass fiber was placed in contact with a semiconductor wafer, the wafer surface in the vicinity of the contact area was exposed. In addition, by immersing the contacted area in an etchant, selective etching only the exposed area is expected. A glass fiber was contacted with a GaAs wafer and was immersed in nitric acid. Laser with the wavelength of 445 nm entered from the edge face. The profiles of the glass fiber were transferred to the GaAs wafer after the light illumination to the glass fiber. The transferred profile with a curvature radius of ∼50 μm and depth of 0.3∼1.2 μm was formed after 5-minute light exposure. By utilizing various glass fiber with different diameter, cylindrical surface with different curvature radius was formed. The difference in the glass fiber radius and the transferred surface was less than 10%.