Liners formed from such a layer may serve as an etch stop for a silicon nitride spacer etch and may be compatible with silicon, oxides of silicon, nitrides of silicon, and oxynitrides of silicon, and other materials that may be used for the insulating spacers 314A/B and the source/drain spacers 318A/B. Alternatively, a higher quality liner layer may be formed, for example by a for example by a LPC