APPARATUS AND METHOD OF FORMING SEMICONDUCTOR DEVICES

摘要

An apparatus to form semiconductor devices includes an inner tube and an outer tube disposed to surround the inner tube. A plate is disposed at first open end of the inner tube to reduce variation between pressures at a first portion and a second portion inside the inner tube. The sum of areas of through-holes disposed on the plate is 10 to 60 percent of the entire area of the plate. The through-holes may include a first through-hole that is disposed at a central portion of the plate, and second through-holes disposed at an edge portion of the plate. The second through-holes are annularly arranged to surround the first through-hole.