Abstract: A process for chemical vapor deposition of borophosphosilicate glass on a silicon wafer at reduced pressure is disclosed herein. The process includes a step of placing a silicon wafer within a reactor tube. The reactor tube is evacuated to a pressure of less than 500 millitorr and is heated to a temperature of not less than 350.degree. C. and not greater than 500.degree. C. A mixture of silane, phosphine and boron trichloride gases is flowed into the reactor tube so that the mixture contacts the silicon wafer. At the same time, a quantity of oxygen is flowed into the reactor tube so that the oxygen also contacts the silicon wafer and intermixes and reacts with the silane, phosphine and boron trichloride gases to form layers of borophosphosilicate glass on the silicon wafer.