Channel-Length-Dependence of Strain Field in Transistor Studied via Scanning Moire Fringe Imaging

We have applied scanning moir´e fringe (SMF) imaging to the quantitative measurement of the strain introduced in n-type channel transistors with embedded SiC in the source and drain. The tensile strain parallel to the channels was reveal with a nano-meter scale spatial resolution. We investigated the strain field in transistors with various channel lengths scaled down to 25 nm, and found that the strain increases up to 0.7% as the channel length shrinks to 35 nm. However, the strain in the channel decreases to 0. 55% as the channel length is scaled from 35 nm down to 25 nm. engineering is routinely applied in the fabrication of ad- semiconductor devices to enhance the mobility of the carriers in transistors. 1,2 The mobility of electrons or holes is boosted when the channel in a transistor is under either a tensile or compressive strain, respectively. embedded in the source/drain region for n-type effect transistors. The lattice parameter of a carbon of