Method of heat-treating a glass substrate

A method of heat-treating a glass substrate having a strain point comprising the steps of:

• forming a film comprising aluminum nitride on a surface of said glass substrate;
• and
• heat-treating said glass substrate at a temperature lying within 50.degree. C. from the strain point of said glass substrate in an ambient atmosphere of nitrogen or a mixture of nitrogen and oxygen,
• wherein said aluminum nitride contains 0.01 to 20 atomic % of oxygen.

A method of heat-treating a glass substrate comprising the steps of:

• forming a film comprising aluminum nitride on a surface of said glass substrate;
• and
• heat-treating said glass substrate in an ambient atmosphere selected from the group consisting of N.sub.2, N.sub.2 O, NH.sub.3 and mixtures thereof and simultaneously annealing said film comprising aluminum nitride,
• wherein said film contains oxygen at 0.001 to 10 atomic %.

A method of heat-treating a glass substrate comprising the steps of:

• forming a film comprising aluminum nitride on a surface of said glass substrate;
• first heat-treating said glass substrate in an ambient atmosphere selected from the group consisting of N.sub.2, N.sub.2 O, NH.sub.3 and mixtures thereof;
• slowly cooling said glass substrate after said first heat-treating step;
• second heat-treating said glass substrate at a temperature lower than a temperature used in said first heat-treating step;
• and
• rapidly cooling said glass substrate after said second heat-treating step.

A method of heat-treating a glass substrate comprising the steps of:

• forming a film comprising aluminum nitride on top and bottom surfaces of said glass substrate;
• and
• heat-treating said glass substrate having said film formed thereon in an ambient atmosphere containing nitrogen,
• wherein said aluminum nitride contains 0.01 to 20 atomic % of oxygen.

A method of heat-treating a glass substrate on which a semiconductor device is to be formed, said method comprising the steps of:

• forming a film comprising aluminum nitride at least on a surface of said glass substrate on which said semiconductor device is to be formed;
• heat-treating said glass substrate;
• slowly cooling said glass substrate at a rate of 0.01.degree. to 0.5.degree. C./min in an ambient atmosphere containing nitrogen;
• and then
• forming said semiconductor device on said glass substrate,
• wherein the step of heat-treating is carried out at a temperature higher than any process temperature at which said semiconductor device is formed on said glass substrate.

A method of heat-treating a glass substrate having a strain point comprising the steps of:

• heat-treating said glass substrate above said strain point;
• slowly cooling said glass substrate after said heat-treating step;
• forming a film comprising aluminum nitride at least on one surface of said glass substrate;
• and
• heat-treating said glass substrate and said film in an ambient atmosphere containing nitrogen to anneal said film comprising aluminum nitride.

A method of heat-treating a glass substrate having a strain point comprising the steps of:

• first heat-treating said glass substrate at a temperature higher than said strain point;
• first cooling said glass substrate after said first heat-treating step at a rate of 0.01.degree. C./min. to 0.5.degree. C./min.;
• second heat-treating said glass substrate after said first cooling step at a temperature lower than said strain point;
• and
• second cooling said glass substrate after said second heat-treating step at a rate of 10.degree. C./min. to 300.degree. C./sec.,
• wherein said method comprises a further step of forming a film on said glass substrate either before or after performing the step of said first heat-treating and before performing the step of said second heat-treating.

A method of heat-treating a glass substrate having a strain point comprising the steps of:

• first heat-treating said glass substrate at a temperature higher than said strain point;
• first cooling said glass substrate after said first heat-treating step at a rate of 0.01.degree. C./min to 0.5.degree. C./min.;
• second heat-treating said glass substrate after said first cooling step at a temperature higher than said strain point;
• and
• second cooling said glass substrate after said second heat-treating step at a rate of 10.degree. C./min. to 300.degree. C./sec,
• wherein said first heat-treating step is carried out at a temperature higher than said second heat-treating step, and
• wherein said method comprises a further step of forming a film on said glass substrate either before or after performing the step of said first heat-treating and before performing the step of said second heat-treating.

A method of heat-treating a glass substrate having a strain point comprising the steps of:

• first heat-treating said glass substrate at a temperature higher than said strain point;
• first cooling said glass substrate after said first heat-treating step at a rate of 0.01.degree. C./min. to 0.5.degree. C./min.;
• second heat-treating said glass substrate after said first cooling step at a temperature higher than said strain point and lower than said temperature at which said first heat-treating is conducted;
• and
• second cooling said glass substrate after said second heat-treating step at a rate of 2.degree. to 200.degree. C./sec.
• wherein said method comprises a further step of forming a film on said glass substrate either before or after performing the step of said first heat-treating and before performing the step of said second heat-treating.

A method of heat-treating a glass substrate having a strain point comprising the steps of:

• heat-treating said glass substrate at a temperature higher than said strain point;
• first cooling said glass substrate after said heat-treating step at a rate of 0.01.degree. C./min. to 0.5.degree. C./min.;
• forming an insulating film on said glass substrate;
• forming a silicon film on said insulating film after said first cooling step;
• crystallizing said silicon film formed on said insulating film;
• and
• second cooling said silicon film formed on said insulating film after said crystallizing step at a rate of 10.degree. C./min. to 300.degree. C./sec.,
• wherein said crystallizing step is carried out at a temperature lower than said heat-treating step.