Semiconductor device preparation method

The invention provides a semiconductor device preparation method. A non-crystallizing region is formed in a semiconductor substrate, and then a source/drain region in a semiconductor device is formed in the non-crystallizing region. The non-crystallizing region can restrain generation of defects at the tail end of the source/drain region, and therefore electric leakage between the source/drain region and the semiconductor substrate of the semiconductor device can be well lowered; besides, after a virtual grid structure is removed, a short channel suppression region is formed in a channel region, the short channel effect of the semiconductor device can be suppressed, and the demand that the feature size of the device gradually decreases is met.