| 摘要 |
PURPOSE:To enable to form in a short time a smooth hole having roundness in a compound semiconductor substrate by a method wherein after the compound semiconductor substrate is etched according to an etching liquid stirred relatively, etching is performed by stopping stirring of the etching liquid. CONSTITUTION:A stirring rotor 13 is rotated, and a compound semiconductor substrate 1 is immersed in an etching liquid 11 in the condition stirring the liquid 11. The substrate 1 thereof is covered with an etching-resistant film leaving a hole forming part. At this time, the liquid 11 flows and circulates continuously without stagnating, a reaction is advanced as a reaction rate-determining process, and reaches the prescribed objective depth in a short time. The shape of the hole is made in a squarish condition like a hole 14a at the point in time thereof. Stirring of the liquid 11 is stopped at a point in time when the reaction reached the prescribed objective depth thereof. Thereupon the process is transferred to a diffusion rate-determining process, and the shape of the hole is regulated to a hole 14 having the rounded corner parts. Accordingly, the smooth hole having roundness is formed in a short time, and productivity is enhanced. |
