System and process for heating semiconductor wafers by optimizing absorption of electromagnetic energy
View Patent ↗An apparatus for heat treating semiconductor wafers is disclosed. The apparatus includes a heating device which contains an assembly linear lamps for emitting light energy onto a wafer. The linear lamps can be placed in various configurations. In accordance with the present invention, tuning devices which are used to adjust the overall irradiance distribution of the light energy sources are included in the heating device. The tuning devices can be, for instance, are lamps or lasers.
1. A process for heating semiconductor substrates comprising:
placing a semiconductor substrate in a processing chamber, said substrate being at least substantially surrounded by a slip free ring; and
directing light energy from a first light energy source onto said slip free ring for indirectly heating said semiconductor substrate, said first light energy source comprising at least one laser.
2. A process as defined in claim 1 , wherein the light energy being emitted by the at least one laser contacts the slip free ring at an angle of incidence of greater than about 40°.
3. A process as defined in claim 1 , wherein the light energy that is emitted by the at least one laser contacts the slip free ring in a p-polarized state, an elliptically polarized state, or near a p-polarized state.
4. A process as defined in claim 1 , wherein said semiconductor substrate is also heated by an electrical resistance heater.
5. A process as defined in claim 1 , further comprising the step of directing light energy from a second light energy source onto the semiconductor substrate for directly heating the semiconductor substrate.
6. A process as defined in claim 1 , wherein said slip free ring is coated with an anti-reflective coating.
7. A process as defined in claim 6 , wherein the anti-reflective coating comprises silicon dioxide or silicon nitride.
8. A process as defined in claim 2 , wherein the light energy being emitted by the at least one laser also contacts the slip free ring in a p-polarized state.
9. A process as defined in claim 1 , wherein the slip free ring comprises silicon carbide.
10. A process as defined in claim 1 , wherein the slip free ring comprises graphite.
11. A process as defined in claim 1 , wherein the slip free ring comprises graphite coated with silicon carbide.
12. A process as defined in claim 1 , wherein the slip free ring comprises quartz.