A method of forming phoslon (PNO) comprising the following steps. A CVD reaction chamber having a reaction temperature of from about 300 to 600.degree. C. is provided. From about 10 to 200 sccm PH.sub.3 gas, from about 50 to 4000 sccm N.sub.2 gas and from about 50 to 1000 sccm NH.sub.3 gas are introduced into the CVD reaction chamber. Either from about 10 to 200 sccm O.sub.2 gas or from about 50 to 1000 sccm N.sub.2O gas is introduced into the CVD reaction chamber. An HFRF power of from about 0 watts to 4 kilowatts is also employed. An LFRF power of from about 0 to 5000 watts may also be employed. Employing a phoslon etch stop layer in a borderless contact fabrication. Employing a phoslon lower etch stop layer and/or a phoslon middle etch stop layer in a dual damascene fabrication.