Semiconductor device manufacturing method and semiconductor device
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorYoshikazu Ohno
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Abstract
A trench 5 for element separation is formed in a silicon substrate 1 by an etching process using an SiO2 film 2 as a mask (FIG. 1B). Side walls 18 are formed in a manner covering the trench 5 laterally (FIG. 1C). Defect-forming ions such as silicon ions are implanted into the silicon substrate 1 with the SiO2 film 2 and side walls 18 used as a mask, whereby a gettering layer 1 is formed only at a bottom of the trench 5.
Claims7
A method for manufacturing a semiconductor device having a trench isolation structure, said method comprising:
- forming a trench forming mask over said silicon substrate;
- etching said silicon substrate using said trench-forming mask so as to form a trench in said silicon substrate;
- forming side walls for covering laterally said trench;
- and
- implanting defect-forming ions into said silicon substrate using said trench-forming mask and said side walls as a mask to form a gettering layer only at a bottom of the trench in said silicon substrate.
A method for manufacturing a semiconductor device having a trench isolation structure, said method comprising:
- furnishing a trench-forming mask over said silicon substrate;
- implanting defect-forming ions, using said trench-forming mask as mask, to form a gettering layer deeper than regions where a trench is to be formed in said silicon substrate;
- and
- etching said silicon substrate by use of said trench-forming mask following implantation of said defect-forming ions, thereby forming said trench in said silicon substrate, wherein the gettering layer is formed only at a bottom of the trench formed in said silicon substrate.
A method for manufacturing a semiconductor device having a trench isolation structure, said method comprising the steps of:
- implanting defect-forming ions into a silicon substrate so as to form a gettering layer in regions where a trench is to be formed in said silicon substrate;
- capturing defective elements into said gettering layer from within said silicon substrate;
- and
- removing said gettering layer having said defective elements captured therein during formation of said trench in said silicon substrate.
Dependencies are inferred from the claim text.