Patent ID: 8293621
Filing Date: 2012-10-23
Classification: H01L

Abstract:
1. A fabrication method of a semiconductor substrate, comprising the steps of: (i) forming a LOCOS oxide film outside a device area of a singlecrystalline Si substrate, the device area being an area for changing into source, drain and channel regions sandwiched by source and drain regions; (ii) forming a gate insulating film on the device area of the singlecrystalline Si substrate; (iii) implanting impurity of a desired first conductivity type of either n type or p type corresponding to a channel region, only into regions for changing respectively into source, drain and channel within the device area of the singlecrystalline Si substrate and implanting impurity of a second conductivity type different from the first conductivity type, into regions for changing respectively into source and drain within the device area so as to form a source region, a drain region and a channel region which together constitute an active layer, each of the source, drain and channel regions being directly adjacent to the singlecrystalline Si substrate; (iv) forming an insulating film with a flat upper surface over a gate electrode formed on the gate insulating film, the gate insulating film, and the LOCOS oxide film; and (v) implanting through the insulating film one or plural kinds of ion selected from a hydrogen ion group or an inactive element ion group so as to form an ion implantation layer with a predetermined depth in the singlecrystalline Si substrate.