Method and apparatus of etching a clean trench in a semiconductor material
First Claim
1. A method of etching in a semiconductor material, comprising the steps of:
- providing a process chamber and placing said semiconductor material on a first electrode in said process chamber;
applying a first power supply to said first electrode of said process chamber at a first power level, the first power supply operating at a first frequency;
simultaneously applying a second power supply to said first electrode at a second power level, the second power supply operating at a second frequency;
introducing a plasma chemistry within the process chamber to selectively etch the semiconductor material;
allowing said plasma chemistry to etch said semiconductor material for a predetermined time period while said first and second power supplies are applied;
subsequently applying said first power supply operating at said first frequency at a third power output level, said third power output level being lower than said first power level;
simultaneously applying said second power supply operating at said second frequency at a fourth power output level which is higher than said second power output level; and
allowing said plasma chemistry to etch said semiconductor material for a second predetermined time period while said first and second power supplies are applied at said third and fourth power output levels, respectively.
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Accused Products
Abstract
An etching apparatus (10) includes a process chamber (12) partially surrounded by an upper electrode (14) and a lower electrode (16). A semiconductor material (18) lies within the process chamber (12) and in contact with the lower electrode (16). The lower electrode (16) is connected to a first power supply (22) operating at a substantially high frequency and is also connected to a second power supply (24) operating at a relatively low frequency. The lower frequency of the second power supply (24) provides a degree of anisotropic control to the trench etching process performed on the semiconductor material (18). The added anisotropic control allows for the elimination of sidewall deposition enhancing materials within a plasma chemistry introduced into the process chamber (12) by a gas distributor (20). Without the requirement of a sidewall deposition enhancing material during trench etching of the semiconductor material (18), buildup of residue due to sidewall deposition does not occur within process chamber (12).
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Citations
16 Claims
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1. A method of etching in a semiconductor material, comprising the steps of:
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providing a process chamber and placing said semiconductor material on a first electrode in said process chamber; applying a first power supply to said first electrode of said process chamber at a first power level, the first power supply operating at a first frequency; simultaneously applying a second power supply to said first electrode at a second power level, the second power supply operating at a second frequency; introducing a plasma chemistry within the process chamber to selectively etch the semiconductor material; allowing said plasma chemistry to etch said semiconductor material for a predetermined time period while said first and second power supplies are applied; subsequently applying said first power supply operating at said first frequency at a third power output level, said third power output level being lower than said first power level; simultaneously applying said second power supply operating at said second frequency at a fourth power output level which is higher than said second power output level; and allowing said plasma chemistry to etch said semiconductor material for a second predetermined time period while said first and second power supplies are applied at said third and fourth power output levels, respectively. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of etching a semiconductor material within a process chamber, comprising the steps of:
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providing an electrode within said process chamber which supports the semiconductor material; executing the first part of a two part process on said semiconductor material for a first predetermined time period, wherein the first part comprises the steps of; (a) applying a first power supply at a first predetermined level to said electrode of a process chamber, the first power supply operating at a first frequency; (b) simultaneously applying a second power supply to the electrode at a second power output level, the second power supply operating at a second frequency, the first frequency being substantially greater than the second frequency to provide anisotropic control of the trench etching; and (c) introducing a plasma chemistry within the process chamber to selectively etch said semiconductor material, the plasma chemistry containing materials that do not produce a buildup of sidewall deposition on areas etched away within said semiconductor material or residue within the process chamber; and subsequently executing the second part of said two part process on said semiconductor material for a second predetermined time period, wherein said second part comprises the steps of; (d) applying said first power supply operating at said first frequency at a third power level; (e) applying said second power supply operating at said second frequency at a fourth power level; and (f) etching said semiconductor material a second time by exciting said plasma chemistry with the energies from said first and second power supplies. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A method of etching a semiconductor material within a process chamber, comprising the steps of:
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providing a process chamber having at least one electrode, said semiconductor material being placed on said electrode; providing a plasma chemistry within said process chamber, said plasma chemistry comprising hydrogen bromide and boron trichloride; executing a three part etching process, wherein the first part comprises the steps of; (a) applying a high frequency power supply to said electrode at a first power output level; (b) simultaneously applying a low frequency power supply to said electrode at a second power output level; and (c) allowing said plasma chemistry to etch said semiconductor material while being excited by said high and low frequency power supplies for a predetermined time period; subsequently executing the second part of said three part process, wherein said second part comprises the steps of; (d) adding chlorine to said plasma chemistry; (e) applying said high frequency power supply to said electrode at said first power output level; (f) simultaneously applying said low frequency power supply to said electrode at said second power output level; and (g) allowing said plasma chemistry to etch said semiconductor material while being excited by said high and low frequency power supplies for a second predetermined time period; and subsequently executing the third part of said three part process, wherein said third part comprises the steps of; (h) removing the hydrogen bromide from said plasma chemistry; (i) applying said high frequency power supply to said electrode at a third power output level; (j) simultaneously applying said low frequency power supply to said electrode at fourth power output level; and (k) allowing the plasma chemistry to etch the semiconductor material while being excited by said high and low frequency signals for a third predetermined time period.
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Specification