Die board mask and method for forming die board mask

Application Number  00129585 Application Date  2000.10.08
Publication Number  1290957 Publication Date  2001.04.11
Priority Information   1999/10/4 JP 283545/1999  
Applicant(s) Name  NEC Corp.  
Inventor(s) Name  Oba Fumihiro  
Patent Agency Code  11021 Patent Agent  wang huimin
AbstractThe subject of the present invention is to enhance the uniformity of the etching rate within the wafer surface in etching from the rear side of a stencil mask (back etching) and to obtain a stencil mask having high accuracy of the pattern position. A high concentration boron-silicon layer 21 and a low concentration boron-silicon layer 22 are formed under the silicon insulating film 11 of an SOI substrate for producing a stencil mask and wet etching is carried out with an alkali solution such as KOH solution.