Method of manufacturing a semiconductor device
OwnerHiromichi Kobayashiinventor
Life of this patent
Estimating the term…
Abstract
A silicon nitride film is first formed on a semiconductor substrate and serves as a polishing stopper film. Then, the silicon nitride film and the semiconductor substrate are etched in a predetermined region to form an isolating trench which partitions an active region. Next, a silicon dioxide film is deposited on the semiconductor substrate so that the isolating trench is filled with the silicon dioxide film. Next, first-stage chemical mechanical polishing (CMP) is performed with a SiO2-contained slurry which can efficiently polish the surface of the silicon dioxide film regardless of level difference. Finally, second-stage CMP is performed with a CeO2-contained slurry ensuring a large polishing selectivity ratio of the silicon dioxide with regard to silicon nitride films.
Claims20
A method of manufacturing a semiconductor device, comprising the steps of:
- forming a silicon nitride film on a semiconductor substrate, said silicon nitride film serving as a polishing stopper film;
- etching said silicon nitride film and said semiconductor substrate in a predetermined region to form an isolating trench which partitions an active region;
- depositing a silicon oxide film on said semiconductor substrate so that said isolating trench is filled with said silicon oxide film;
- polishing said silicon oxide film being in an exposed state to reduce level difference in a surface thereof, by employing a first slurry suitable for polishing a silicon oxide film and also suitable for reducing said level difference or making said level difference gentle;
- and
- polishing said silicon oxide film until said silicon nitride film is exposed, by employing a second slurry which contains cerium dioxide, after said level difference in the surface of said silicon oxide film has been reduced.
A method of manufacturing a semiconductor device, comprising the steps of:
- forming a silicon nitride film on a semiconductor substrate, said silicon nitride film serving as a polishing stopper film;
- etching said silicon nitride film and said semiconductor substrate in a predetermined region to form an isolating trench which partitions an active region;
- depositing a silicon oxide film on said semiconductor substrate so that said isolating trench is filled with said silicon oxide film;
- filling a surface depression in said silicon oxide film with a flattening material to reduce level difference in a surface of said silicon oxide film;
- and
- polishing said silicon oxide film until said silicon nitride film is exposed, by employing a second slurry which contains cerium dioxide, after said level difference in the surface of said silicon oxide film has been reduced.
A method of manufacturing a semiconductor device, comprising the steps of:
- forming a silicon nitride film on a semiconductor substrate, said silicon nitride film serving as a polishing stopper film;
- etching said silicon nitride film and said semiconductor substrate in a predetermined region to form an isolating trench which partitions an active region;
- depositing a silicon oxide film on said silicon substrate so that said isolating trench is filled with said silicon oxide film;
- performing wet chemical etching on a surface of said silicon oxide film to reduce level difference in the surface of said silicon oxide film;
- and
- polishing said silicon oxide film until said silicon nitride film is exposed, by employing a second slurry which contains cerium dioxide, after said level difference in the surface of said silicon oxide film has been reduced.
Dependencies are inferred from the claim text.