Method of manufacturing semicontor device having trench isolation

A method of manufacturing a semiconductor device comprising a MOS transistor on an SOI layer of an SOI substrate obtained by sequentially stacking a semiconductor substrate, a buried insulating film, and said SOI layer, and a trench isolation oxide film which defines an active region serving as a region in which said MOS transistor is formed and electrically isolates said MOS transistor, comprising the steps of:

• (a) forming an auxiliary film used for forming said trench isolation oxide film on said SOI layer;
• (b) forming a trench penetrating said auxiliary film and reaching a predetermined depth in said SOI layer by trench etching;
• (c) measuring a thickness of said SOI layer remained after formation of said trench and, on the basis of said thickness of said SOI layer remained, calculating the latest etching rate for said SOI layer;
• and
• (d) giving data of said latest etching rate to said trench etching step of a different manufacture lot of said semiconductor device.

A method of manufacturing a semiconductor device,

• said semiconductor device comprising a MOS transistor on an SOI layer of an SOI substrate obtained by sequentially stacking a semiconductor substrate, a buried insulating film, and said SOI layer, and a trench isolation oxide film which defines an active region serving as a region in which said MOS transistor is formed and electrically isolates said MOS transistor, wherein
• said trench isolation oxide film includes a combined isolation oxide film which is a combination of a full isolation oxide film penetrating said SOI layer and reaching said buried insulating film of said SOI substrate, and a partial isolation oxide film having the SOI layer under said partial isolation oxide film, and
• in said combined isolation oxide film, a portion around the active region except for a portion near a gate electrode of said MOS transistor is constructed by said full isolation oxide film and the other portion is constructed by said partial isolation oxide film,
• the method comprises the steps of:
• (a) preparing field data of a source/drain layer for forming a partial trench which defines a region in which the source/drain layer is formed in said active region;
• (b) preparing gate data for forming said gate electrode;
• and
• (c) preparing full isolation data for forming said full isolation oxide film, and
• said step (c) includes a step of obtaining said full isolation data from said field data and said gate data.