High quality deep trench oxide

摘要

An integrated circuit including a trench in the substrate with a high quality trench oxide grown on the sidewalls and the bottom of the trench where the ratio of the thickness of the high quality trench oxide formed on the sidewalls to the thickness formed on the bottom is less than 1.2. An integrated circuit including a trench with high quality oxide is formed by first growing a sacrificial oxide in dilute oxygen at a temperature in the range of 1050° C. to 1250° C., stripping the sacrificial oxide, growing high quality oxide in dilute oxygen plus trans 1,2 dichloroethylene at a temperature in the range of 1050° C. to 1250° C., and annealing the high quality oxide in an inert ambient at a temperature in the range of 1050° C. to 1250° C.

主权项

1. A method of forming an integrated circuit, comprising the steps:
forming a trench pattern on a silicon substrate of the integrated circuit; etching a trench into the silicon substrate to a depth between 0.6 um and 6 um; removing the trench pattern; performing a plasma soft etch; growing a sacrificial oxide in dilute oxygen ambient at a temperature in the range of 1050° C. to 1250° C. to a thickness in the range of 10 nm to 50 nm; removing the sacrificial oxide by etching in dilute HF; growing a high quality trench oxide at a temperature in the range of 1050° C. to 1250° C. in an ambient of nitrogen, oxygen, and trans 1,2 dichloroethylene (TLC); annealing the high quality trench oxide in an inert ambient at a temperature in the range of 1050° C. to 1250° C.; and depositing polysilicon to fill the trench.