Method of selective removal of SiGe alloys
First Claim
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1. A method of forming a semiconductor substrate, comprising:
- providing a structure comprising a first layer having a first oxidation rate disposed over a second layer having a second oxidation rate, wherein the first oxidation rate is greater than the second oxidation rate;
reacting said first layer to form a sacrificial layer; and
removing said sacrificial layer to expose said second layer, wherein the second layer comprises a strained semiconductor.
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Abstract
A method is disclosed of forming buried channel devices and surface channel devices on a heterostructure semiconductor substrate. In an embodiment, the method includes the steps of providing a structure including a first layer having a first oxidation rate disposed over a second layer having a second oxidation rate wherein the first oxidation rate is greater than the second oxidation rate, reacting said first layer to form a sacrificial layer, and removing said sacrificial layer to expose said second layer.
184 Citations
13 Claims
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1. A method of forming a semiconductor substrate, comprising:
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providing a structure comprising a first layer having a first oxidation rate disposed over a second layer having a second oxidation rate, wherein the first oxidation rate is greater than the second oxidation rate;
reacting said first layer to form a sacrificial layer; and
removing said sacrificial layer to expose said second layer, wherein the second layer comprises a strained semiconductor.
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2. A method of forming a semiconductor substrate, comprising:
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providing a structure comprising a first aver having a first oxidation rate disposed over a second layer having a second oxidation rate, wherein the first oxidation rate is greater than the second oxidation rate;
reacting said first layer to form a sacrificial layer; and
removing said sacrificial layer to expose said second layer, wherein the second layer comprises Si.
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3. A method of forming a semiconductor substrate, comprising:
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providing a structure comprising a first layer having a first oxidation rate disposed over a second layer having a second oxidation rate, wherein the first oxidation rate is greater than the second oxidation rate;
reacting said first layer to form a sacrificial layer; and
removing said sacrificial layer to expose said second layer, wherein said semiconductor substrate further comprises an insulator layer disposed beneath said second layer. - View Dependent Claims (4)
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5. A method of forming a semiconductor substrate, comprising:
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providing a structure comprising a first layer having a first oxidation rate disposed over a second layer having a second oxidation rate, wherein the first oxidation rate is greater than the second oxidation rate;
reacting said first layer to form a sacrificial layer, wherein said reacting comprises thermal oxidation performed at or below a temperature of approximately 850°
C.; and
removing said sacrificial layer to expose said second layer.
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6. A method of forming a semiconductor substrate, comprising:
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providing a structure comprising a first layer having a first oxidation rate disposed over a second layer having a second oxidation rate, wherein the first oxidation rate is greater than the second oxidation rate;
reacting said first layer to form a sacrificial layer; and
removing said sacrificial layer to expose said second layer, wherein said step of reacting said first layer to form a sacrificial layer comprises chemical oxidation.
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7. A method of forming a semiconductor substrate, comprising:
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providing a structure comprising a first layer having a first oxidation rate disposed over a second layer having a second oxidation rate, wherein the first oxidation rate is greater than the second oxidation rate;
reacting said first layer to form a sacrificial layer; and
removing said sacrificial aver to expose said second layer, wherein said step of reacting said first layer to form a sacrificial layer is performed on a first region of said first layer and not on a second region of said first layer. - View Dependent Claims (8, 9, 10, 11)
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12. A method of forming devices on a substrate said method comprising the steps of:
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providing a structure comprising a SiGe layer disposed over a strained semiconductor layer; and
selectively removing said SiGe layer in a first region but not in a second region such that a surface channel device may be formed on said first region and a buried channel device may be formed on said second region.
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13. A method of forming devices on a substrate, said method comprising the steps of
providing a structure comprising a SiGe layer disposed over a strained semiconductor layer; -
oxidizing said SiGe layer to form a SiGe oxide in a first region but not in a second region of said structure;
removing said SiGe oxide; and
forming a surface channel device in said first region and a buried channel device in said second region such that the strained semiconductor layer serves as the channel layer of each device.
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Specification