Method to fabricate the MOS gate

A method of fabricating gate electrodes in the manufacture of an integrated circuit device comprising:

• depositing a layer of silicon oxide on the surface of a semiconductor substrate;
• depositing a layer of silicon nitride overlying said silicon oxide layer;
• depositing a layer of tetraethoxysilane (TEOS) oxide overlying said silicon nitride layer;
• etching away said TEOS oxide layer, said silicon nitride layer, and said silicon oxide layer where they are not covered by a mask to leave a dielectric stack wherein said dielectric stack has a width equal to the spacing between two of planned said gate electrodes;
• growing a gate oxide layer on the surface of said semiconductor substrate not covered by said dielectric stack;
• depositing a polysilicon layer overlying said gate oxide layer and said dielectric stack;
• etching back said polysilicon layer to leave spacers on the sidewalls of said dielectric stack;
• depositing a dielectric layer overlying said dielectric stack and said spacers;
• polishing back said dielectric layer whereby an upper portion of said dielectric stack and said spacers are polished away;
• and
• removing remaining said dielectric layer and said dielectric stack whereby said spacers remain forming said gate electrodes having said gate oxide layer thereunder to complete fabrication of said gate electrodes in the manufacture of said integrated circuit device.

A method of fabricating gate electrodes in the manufacture of an integrated circuit device comprising:

• providing a dielectric stack on the surface of a semiconductor substrate;
• etching away said dielectric stack where it is not covered by a mask wherein remaining said dielectric stack has a width equal to the spacing between two of planned said gate electrodes;
• growing a gate oxide layer on the surface of said semiconductor substrate not covered by said dielectric stack;
• depositing a polysilicon layer overlying said gate oxide layer and said dielectric stack;
• etching back said polysilicon layer to leave spacers on the sidewalls of said dielectric stack wherein said spacers have a width as small as between 300 and 800 Angstroms;
• depositing a dielectric layer overlying said dielectric stack and said spacers;
• polishing back said dielectric layer whereby upper portions of said dielectric stack and said spacers are polished away wherein said upper portions comprise ⅓ of said dielectric stack;
• and
• removing remaining said dielectric layer and said dielectric stack whereby said spacers remain forming said gate electrodes having said gate oxide layer thereunder to complete fabrication of said gate electrodes in the manufacture of said integrated circuit device.

A method of integrating the fabrication of both narrow and wide gate electrodes in the manufacture of an integrated circuit device comprising:

• providing a dielectric stack on the surface of a semiconductor substrate;
• etching away said dielectric stack where it is not covered by a mask wherein remaining said dielectric stack has a width equal to the spacing between two of planned said narrow gate electrodes;
• growing a gate oxide layer on the surface of said semiconductor substrate not covered by said dielectric stack;
• depositing a polysilicon layer overlying said gate oxide layer and said dielectric stack;
• forming a first mask over said polysilicon layer where said wide gate electrodes are to be formed;
• etching back said polysilicon layer not covered by said first mask to leave spacers on the sidewalls of said dielectric stack;
• thereafter removing said first mask;
• depositing a dielectric layer overlying said substrate;
• thereafter polishing back said dielectric layer whereby upper portions of said dielectric stack and said spacers are polished away wherein said upper portions comprise about ⅓ of said dielectric stack;
• removing remaining said dielectric layer and said dielectric stack whereby said spacers remain forming said narrow gate electrodes having said gate oxide layer thereunder;
• forming a second mask covering said narrow gate electrodes and forming a pattern over said polysilicon layer for forming said wide gate electrodes;
• patterning said polysilicon layer not covered by said second mask to form said wide gate electrodes to complete integration of said fabrication of both narrow and wide gate electrodes in the manufacture of said integrated circuit device.