Variable frequency microwave (VFM) processes and applications in semiconductor thin film fabrications
Methods and apparatus for processing a substrate are described herein. A vacuum multi-chamber deposition tool can include a degas chamber with both a heating mechanism and a variable frequency microwave source. The methods described herein use variable frequency microwave radiation to increased quality and speed of the degas process without damaging the various components.
1. A method for processing a substrate, comprising:
positioning a substrate in a physical vapor deposition chamber, the substrate comprising a first surface;
depositing an uncured layer comprising a polymer, an epoxy or combinations thereof over the first surface of the substrate; and
performing a hard-cure of the uncured layer in the physical vapor deposition chamber, the hard-cure comprising:
heating at least the uncured layer to a degas temperature ranging from about 85 degrees Celsius to about 95 degrees Celsius, the degas temperature being less than a hard-cure temperature for the uncured layer;
setting the physical vapor deposition chamber to a hard-cure pressure, the hard-cure pressure being under 100 mTorr;
directing a source of microwave radiation toward the uncured layer, the source of microwave radiation producing microwave radiation at a frequency selected from a frequency range of less than 7 GHz; and
delivering the microwave radiation at a variable frequency from the source of microwave radiation to the uncured layer to heat the uncured layer to the hard-cure temperature, the variable frequency comprising two or more frequencies selected from the frequency range, the variable frequency changing over a period of time, wherein the degas temperature, the hard-cure pressure and the microwave radiation act in conjunction to produce a cured and degassed layer.
2. The method of claim 1 , wherein the hard-cure temperature is between 300° C. and 400° C.
3. The method of claim 1 , further comprising depositing a seed layer.
4. The method of claim 1 , wherein the hard-cure pressure is less than 1 mTorr.
5. The method of claim 1 , wherein the frequency range is from 5850 MHz to 6650 MHz.
6. The method of claim 1 , wherein the variable frequency comprises two or more frequencies, each frequency varying from a previous frequency by from 200 MHz to 280 MHz.
7. The method of claim 1 , wherein the period of time is between 6 minutes and 10 minutes.
8. The method of claim 1 , wherein the variable frequency change occurs during the period of time in a time interval of from 20 microseconds to 30 microseconds.
9. The method of claim 1 , further comprising flowing an inert gas into the physical vapor deposition chamber to clear the physical vapor deposition chamber of outgassed substances.
10. A method for processing a substrate, comprising:
positioning a substrate in a physical vapor deposition chamber, the substrate comprising a first surface;
depositing an uncured layer comprising a polymer, an epoxy, or combinations thereof over the first surface of the substrate; and
performing a hard-cure of the uncured layer in the physical vapor deposition chamber, the hard-cure comprising:
heating at least the uncured layer to a degas temperature ranging from about 85 degrees Celsius to about 95 degrees Celsius, the degas temperature being less than a hard-cure temperature for the uncured layer;
setting the physical vapor deposition chamber to a hard-cure pressure, the hard-cure pressure being under 100 mTorr;
directing a source of microwave radiation toward the uncured layer, the source of microwave radiation producing microwave radiation at a frequency selected from a frequency range of less than 7 GHz; and
delivering the microwave radiation at a variable frequency from the source of microwave radiation to the uncured layer to heat the uncured layer to the hard-cure temperature, the variable frequency comprising two or more frequencies selected from the frequency range, the variable frequency changing over a period of time, wherein each of the two or more frequencies varying from a previous frequency by from 200 MHz to 280 MHz, and wherein the degas temperature, the hard-cure pressure and the microwave radiation act in conjunction to produce a cured and degassed layer.
11. The method of claim 10 , wherein the hard-cure temperature is between 300° C. and 400° C.
12. The method of claim 10 , further comprising depositing a seed layer.
13. The method of claim 10 , wherein the hard-cure pressure is less than 1 mTorr.
14. The method of claim 10 , wherein the frequency range is from 5850 MHz to 6650 MHz.
15. The method of claim 10 , wherein the period of time is between 6 minutes and 10 minutes.
16. The method of claim 10 , wherein the variable frequency change occurs during the period of time in a time interval of from 20 microseconds to 30 microseconds.
17. The method of claim 10 , further comprising flowing an inert gas into the physical vapor deposition chamber to clear the physical vapor deposition chamber of outgassed substances.
18. A method for processing a substrate, comprising:
positioning a substrate in a physical vapor deposition chamber, the substrate comprising a first surface;
depositing an uncured layer comprising a polymer, an epoxy or combinations thereof over the first surface of the substrate; and
performing a hard-cure of the uncured layer in the physical vapor deposition chamber, the hard-cure comprising:
heating at least the uncured layer to a degas temperature ranging from about 85 degrees Celsius to about 95 degrees Celsius, the degas temperature being less than a hard-cure temperature for the uncured layer;
setting the physical vapor deposition chamber to a hard-cure pressure, the hard-cure pressure being under 100 mTorr;
directing a source of microwave radiation toward the uncured layer, the source of microwave radiation producing microwave radiation at a frequency selected from a frequency range of less than 7 GHz; and
delivering the microwave radiation at a variable frequency from the source of microwave radiation to the uncured layer to heat the uncured layer to the hard-cure temperature, the variable frequency comprising two or more frequencies selected from the frequency range, the variable frequency changing over a period of time, the variable frequency comprising two or more frequencies, each of the two or more frequencies varying from a previous frequency by from 200 MHz to 280 MHz, wherein the variable frequency change occurs during the period of time in a time interval of from 20 microseconds to 30 microseconds, and wherein the degas temperature, the hard-cure pressure and the microwave radiation act in conjunction to produce a cured and degassed layer.