Deposition of tensile and compressive stressed materials
A method of depositing tensile or compressively stressed silicon nitride on a substrate is described. Silicon nitride having a tensile stress with an absolute value of at least about 1200 MPa can be deposited from process gas comprising silicon-containing gas and nitrogen-containing gas, maintained in an electric field having a strength of from about 25 V/mil to about 300 V/mil. The electric field is formed by applying a voltage at a power level of less than about 60 Watts across electrodes that are spaced apart by a separation distance that is at least about 600 mils. Alternatively, silicon nitride having a compressive stress with an absolute value of at least about 2000 MPa can be formed in an electric field having a strength of from about 400 V/mil to about 800 V/mil.
1. A method of depositing tensile-stressed silicon nitride on a substrate, the method comprising:
(a) placing the substrate in a process zone;
(b) introducing a process gas into the process zone, the process gas comprising silicon-containing gas and nitrogen-containing gas; and
(c) depositing on the substrate, tensile-stressed silicon nitride having a tensile stress with an absolute value of at least about 1200 MPa, by maintaining in the process zone, an electric field having a field strength of from about 25 V/mil to about 300 V/mil, wherein the electric field is formed by applying a voltage at a power level of less than about 60 Watts across electrodes that are spaced apart by a separation distance that is at least about 600 mils.
2. A method according to claim 1 comprising maintaining an electric field having a field strength of from about 75 V/mil to about 100 V/mil.
3. A method according to claim 1 comprising applying a voltage at a power level of less than about 30 Watts across electrodes.
4. A method according to claim 1 comprising separating the electrodes by a separation distance of from about 700 mils to about 1000 mils.
5. A method according to claim 1 comprising maintaining an electric field having a field strength that is sufficiently high to deposit silicon nitride having a tensile stress with an absolute value of at least about 1400 MPa.
6. A method according to claim 1 comprising applying a voltage having a frequency of from about 3 MHz to about 60 MHz.
7. A method according to claim 1 wherein the process gas comprises silane, NH 3 and N 2 .
8. A method of depositing tensile-stressed silicon nitride on a substrate, the method comprising:
(a) placing the substrate in a process zone;
(b) introducing a process gas into the process zone, the process gas comprising silane, NH 3 and N 2 ; and
(c) depositing on the substrate, tensile-stressed silicon nitride having a tensile stress with an absolute value of at least about 1400 MPa, by maintaining in the process zone, an electric field having a field strength of from about 75 V/mil to about 100 V/mil, wherein the electric field is formed by applying a voltage at a power level of less than about 30 Watts across electrodes that are spaced apart by a separation distance of from about 700 mils to about 1000 mils.
9. A method according to claim 8 comprising applying a voltage having a frequency of from about 13 MHz to about 14 MHz.
10. A method of depositing compressive-stressed silicon nitride on a substrate, the method comprising:
(a) placing the substrate in a process zone;
(b) introducing a process gas into the process zone, the process gas comprising silicon-containing gas and nitrogen-containing gas; and
(c) depositing on the substrate, compressive-stressed silicon nitride having a compressive stress with an absolute value of at least about 2000 MPa, by maintaining in the process zone, an electric field having a field strength of from about 400 V/mil to about 800 V/mil, wherein the electric field is formed by applying a voltage at a power level of at least about 80 Watts across electrodes that are spaced apart by a separation distance that is less than about 400 mils.
11. A method according to claim 10 comprising maintaining an electric field having a field strength of from about 500 V/mil to about 700 V/mil.
12. A method according to claim 10 comprising applying a voltage at a power level of at least about 100 Watts across the electrodes.
13. A method according to claim 10 comprising separating the electrodes by a separation distance of less than about 200 mils.
14. A method according to claim 10 comprising separating the electrodes by a separation distance of from about 100 mils to about 325 mils.
15. A method according to claim 10 comprising maintaining an electric field having a field strength that is sufficiently high to deposit silicon nitride having a compressive stress with an absolute value of at least about 2800 MPa.
16. A method according to claim 10 comprising applying a voltage having a frequency of from about 100 kHz to about 1 MHz.
17. A method according to claim 10 wherein the process gas comprises silane, NH 3 and N 2 .
18. A method of depositing compressive-stressed silicon nitride on a substrate, the method comprising:
(a) placing the substrate in a process zone;
(b) introducing a process gas into the process zone, the process gas comprising silane, NH 3 and N 2 ; and
(c) depositing on the substrate, compressive-stressed silicon nitride having a compressive stress with an absolute value of at least about 2800 MPa, by maintaining in the process zone, an electric field having a field strength of from about 500 V/mil to about 700 V/mil, wherein the electric field is formed by applying a voltage at a power level of at least about 100 Watts across electrodes that are spaced apart by a separation distance of from about 100 mils to about 325 mils.
19. A method according to claim 18 comprising applying a voltage having a frequency of from about 300 kHz to about 400 kHz.