Method for fabricating a semiconductor device

A method of forming an insulation film on a substrate having a main surface including a patterned surface portion with recesses therein and a non-patterned surface portion, comprising:

• forming a first insulation film, by a first thermal chemical vapor deposition (CVD) process employing a supply of a film forming gas and in a vacuum condition at a first pressure, on the main surface and so as to fill the recesses in the patterned surface portion thereof;
• while continuing the supply of the film forming gas and maintaining the vacuum condition, forming a second insulation film by a second thermal CVD process as a continuation of the first CVD process and at a second pressure which is lower than the first pressure;
• and
• subjecting both of said first and second insulation films to reflow annealing under an atmosphere including water vapor at a temperature of 750° C. or less.

A method of fabricating a semiconductor device, comprising:

• forming a first insulation film by a first thermal chemical vapor deposition (CVD) process, employing a supply of a film forming gas and in a vacuum condition at a first pressure, on a main surface of a substrate having patterned recesses therein;
• and
• after the patterned recesses are substantially filled with the first insulation film, and while continuing the supply of the film forming gas and maintaining the vacuum condition at a second pressure which is lower than the first pressure, forming a second insulation film by a second thermal CVD process as a continuation of the first CVD process, wherein:
• the first CVD process employs a growth pressure of at least 600 Torr, and the second CVD process employs a growth pressure of not greater than 600 Torr, and
• each of said first and second insulation films is formed of alcoxylane, an alcoxyl compound of a conductive impurity and ozone.

A method of fabricating a semiconductor device, comprising:

• forming a first insulation film by a first thermal chemical vapor deposition (CVD) process, employing a supply of a film forming gas and in a vacuum condition at a first pressure, on a main surface of a substrate having patterned recesses therein;
• after the patterned recesses are substantially filled with the first insulation film, and while continuing the supply of the film forming gas and maintaining the vacuum condition at a second pressure which is lower than the first pressure, forming a second insulation film by a second thermal CVD process as a continuation of the first CVD process;
• and
• subjecting both of said first and second insulation films to reflow annealing in a nitrogen and oxygen combination atmosphere at 700° C. or more and to fill a recess having an aspect ratio of 4 or more.

A method of fabricating a semiconductor device, comprising:

• forming a first insulation film by a first thermal chemical vapor deposition (CVD) process, employing a supply of a film forming gas and in a vacuum condition at a first pressure, on a main surface of a substrate having patterned recesses therein;
• after the patterned recesses are substantially filled with the first insulation film, and while continuing the supply of the film forming gas and maintaining the vacuum condition at a second pressure which is lower than the first pressure, forming a second insulation film by a second thermal CVD process as a continuation of the first CVD process, wherein each of said first and second insulation films further comprises both Boron and Phosphorus conductive impurities;
• and
• subjecting both of said first and second insulation films to reflow annealing in a nitrogen and oxygen combination atmosphere at 700° C. or more and to fill a recess having an aspect ratio of 4 or more.

A method of forming an insulation film on a substrate having a main surface including a patterned surface portion with recesses therein and a non-patterned surface portion, comprising:

• forming a first insulation film, by a first thermal chemical vapor deposition (CVD) process employing a supply of a film forming gas and in a vacuum condition at a first pressure, on the main surface and so as to fill the recesses in the patterned surface portion thereof;
• and
• while continuing the supply of the film forming gas and maintaining the vacuum condition, forming a second insulation film by a second thermal CVD process as a continuation of the first CVD process and at a second pressure which is lower than the first pressure, wherein:
• the first CVD process employs a growth pressure of at least 600 Torr, and the second CVD process employs a growth pressure of not greater than 600 Torr, and each of said first and second insulation films is formed of alcoxylane, an alcoxyl compound of a conductive impurity and ozone.

A method of forming an insulation film on a substrate having a main surface including a patterned surface portion with recesses therein and a non-patterned surface portion, comprising:

• forming a first insulation film, by a first thermal chemical vapor deposition (CVD) process employing a supply of a film forming gas and in a vacuum condition at a first pressure, on the main surface and so as to fill the recesses in the patterned surface portion thereof;
• while continuing the supply of the film forming gas and maintaining the vacuum condition, forming a second insulation film by a second thermal CVD process as a continuation of the first CVD process and at a second pressure which is lower than the first pressure;
• and
• subjecting both of said first and second insulation fields to reflow annealing in a nitrogen and oxygen combination atmosphere at 700° C. or more and to fill a recess having an aspect ratio of 4 or more.