METHOD OF SUPPRESSING ANOMALOUS INCREASES IN THE THRESHOLD VOLTAGE OF A SEMICONDUCTOR DEVICE

In an example embodiment, a method for manufacturing a semiconductor device having shallow trench isolation comprises forming a trench region in a substrate having a substantially planar bottom, a first and second sidewall. In the trench region, the method forms a dielectric liner on the bottom and the first and second sidewalls. The dielectric liner is a silicon nitride compound. The dielectric liner minimizes the anomalous increases in threshold voltage with width (Vt versus W) owing to transient enhanced up-diffusion of the channel profile induced by source/drain implant damage. In addition, the anomalous increase in Vt versus W associated with the formation of an interstitial gradient in sub-micron devices is reduced. By using a nitrided liner, Vt roll off due to boron segregation is also minimized.