Removal method for super junction sacrificial oxide layer

The invention discloses a removal method for a super junction sacrificial oxide layer. The method comprises the following steps: preprocessing a silicon slice by using deionized water (DIW); and removing a sacrificial oxide layer by using dilute hydrofluoric acid (DHF). Due to the fact that the silicon slice is preprocessed by water before the super junction sacrificial oxide layer which is in a deep trench groove is etched by the DHF, the water can infiltrate the deep trench groove, and then the DHF can directly replace the water in the deep trench groove and has a fast and thorough reaction with the sacrificial oxide layer in the deep trench groove, so that high-concentration DHF can be used for completely removing the sacrificial oxide layer in the deep trench groove. Finally, process time is shortened, production efficiency is improved, meanwhile, super junction puncture voltage random failure rate can be reduced, and product yield is improved.