Maybe the chemically etched can form the taper but the hole dimension maybe too big if only etch from one side.

化学蚀刻的模板也可以成锥形，但是如果只从一面腐蚀，开孔尺寸可能太大。

youdao

Cobalt phase was chemically etched to certain depth beneath the surface and porous layer was formed after YG8 cemented carbide had been soaked in aqueous solution of dilute nitric acid.

YG8硬质合金经稀硝酸水溶液化学侵蚀后，表面一定深度内的粘结相钴将被化学刻蚀掉，引起表层疏松。

youdao

In particular, the processes by which the circuit pattern is first projected on to a chip's surface lithographically, and then etched on to it chemically, will need to be altered to take account of the fact that the surface is curved.

ECONOMIST: Semiconductors