Surface finishing of SOI substrates using an EPI process
AssigneeSilicon Genesis Corporation
InventorsSien G. Kang, Igor J. Malik
Life of this patent
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Abstract
A method for treating a film of material, which can be defined on a substrate, e.g., silicon. The method includes providing a substrate comprising a cleaved surface, which is characterized by a predetermined surface roughness value. The substrate also has a distribution of hydrogen bearing particles defined from the cleaved surface to a region underlying said cleaved surface. The method also includes increasing a temperature of the cleaved surface to greater than about 1,000 Degrees Celsius while maintaining the cleaved surface in an etchant bearing environment to reduce the predetermined surface roughness value by about fifty percent and greater. Preferably, the value can be reduced by about eighty or ninety percent and greater, depending upon the embodiment.
Claims17
A dry method for finishing SOI substrates, said method comprising:
- providing an SOI substrate comprising a cleaved surface, said cleaved surface having a first surface roughness value;
- performing a hydrogen treatment to increase a concentration of hydrogen of said cleaved surface;
- and
- performing an etchant and thermal treatment after the hydrogen treatment, the etchant and thermal treatment comprising:
- increasing a temperature of an environment associated with said cleaved surface to greater than about 1,000° Celsius;
- and
- contacting said cleaved surface with a hydrogen bearing environment at least when said temperature of said environment is greater than about 1,000° Celsius to reduce said first surface roughness value by at least about eighty percent to a second surface roughness value, said hydrogen bearing environment including at least an HCl gas and a hydrogen gas;
- whereupon the cleaved surface having the second roughness value is substantially planarized.
A dry method for finishing SOI wafers, said method comprising:
- providing an SOI wafer comprising a main surface that has been cleaved, said cleaved main surface having a first surface roughness value;
- performing a hydrogen treatment to increase a hydrogen concentration of said cleaved main surface;
- and
- performing an etchant and thermal treatment after the hydrogen treatment, the etchant and thermal treatment comprising:
- increasing a temperature of an environment associated with said cleaved main surface to greater than about 1,000° Celsius;
- and
- contacting said cleaved main surface with a hydrogen bearing environment at least when said temperature of said environment is greater than about 1,000° Celsius to reduce said first surface roughness value by at least about eighty percent to a second surface roughness value, said hydrogen bearing environment including at least an HCl gas and a hydrogen gas;
- wherein the main surface is substantially planarized in its entirety to the second roughness value, the planarized main surface providing a surface whereon a plurality of devices are later defined.
Dependencies are inferred from the claim text.