Substrate with strained and relaxed silicon regions

摘要

A method is provided for forming an integrated circuit. A trench is formed in a substrate. Subsequently, a silicon-germanium feature is formed in the trench, and an etch stop layer is formed on the substrate and on the silicon-germanium feature. Lastly, a silicon device layer is formed on the etch stop layer. The silicon device layer has a tensily-strained region overlying the silicon-germanium feature. Regions of the silicon device layer not overlying the silicon-germanium feature are less strained than the tensily-strained region. The tensily-strained region of the silicon device layer may be further processed into channel features in n-type field effect transistors with improved charge carrier mobilities and device drive currents.

主权项

1. A method for forming an integrated circuit comprising the steps of:
forming a trench in a first substrate; forming a silicon-germanium feature in the trench; forming an etch stop layer on the first substrate and on the silicon-germanium feature; and forming a silicon device layer on the etch stop layer, the silicon device layer comprising a first portion with a tensily-strained region overlying the silicon-germanium feature, and a second portion not overlying the silicon-germanium feature which is less tensily-strained relative to the first portion.