A method for making an oxide layer on a silicon substrate produces an oxide layer including graded portions with greatly reduced stress. The method includes growing a first oxide portion over a substrate by upwardly ramping the substrate to a first temperature lower than a SiO2 viscoelastic temperature. Thereafter a second oxide portion is grown between the first oxide portion and the silicon substrate by exposing the silicon substrate to an oxidizing ambient at a second temperature higher than the SiO2 viscoelastic temperature. The second oxide portion may have a thickness in a range of about 25 to 50% of a total thickness of the graded oxide layer.