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

Peter shouted for help because he knew the hole meant that the sea was making its way through the sea wall, but no answer came.

彼得知道这个洞意味着海水正在穿过海堤，所以他大声呼救，但没人应答。

youdao

We were in a hole, but I was proud with the way we came back.

我们虽然身陷困境，但我很为我们能像这样东山再起感到自豪。

《柯林斯英汉双解大词典》

It looks severely damaged. But the huge hole, the names and other marks seem to add to its sound.

VOA: special.2010.05.12

But the box is built so you can not turn the bar toward the hole.

VOA: special.2010.03.22

But the hole we have to fill is much deeper and the global aftershocks are much greater.

WHITEHOUSE: President Obama Holds a Press Conference on the Economy

Not only is borrowing higher, but the hole in the economy is also worse than it was then.

BBC: Margaret Thatcher: The economy now and then

But the hole in the public finances has expanded to absorb it.

BBC: Digging to stand still