Etching trenches in a substrate
First Claim
1. A method for providing an electronic product containing one or more trenches, comprising:
- providing a substrate comprising a semiconductor material body having a principal surface;
forming a dielectric layer over the principal surface of the semiconductor material body;
producing at least one etch window in the dielectric layer;
introducing etch stabilizing ions into a portion of the semiconductor material body of the substrate proximate the principal surface and through the etch window in the dielectric layer, the etch stabilizing ions consisting essentially of fluorine ions implanted to a fluorine ion concentration greater than 5E18 ions per cm3; and
forming the one or more trenches by etching away at least part of the semiconductor material body of the substrate containing the etch stabilizing ions through the etch window in the dielectric layer, the one or more trenches each comprising a cavity or micro-cavity extending into, but not through the semiconductor material body of the substrate, and having a width between about 500 and 1200 micrometers.
29 Assignments
0 Petitions
Accused Products
Abstract
Etch stabilizing ions (37) are introduced, e.g., by ion implantation (34), into a portion (36) of a substrate (20) underlying an etch window (24) in a masking layer (22) covering the substrate (20), where a trench (26) is desired to be formed. When the portion (36) of the substrate (20) containing the etch stabilizing ions (37) is etched to form the trench (26), the etch stabilizing ions (37) are progressively released at the etch interface (28′) as etching proceeds, substantially preventing gas micro-bubbles or other reaction products at the etch interface (28′) from disrupting etching. Using this method (700), products containing trenches (26) are much more easily formed and such trenches (26) have much smoother interior surface (28).
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Citations
17 Claims
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1. A method for providing an electronic product containing one or more trenches, comprising:
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providing a substrate comprising a semiconductor material body having a principal surface; forming a dielectric layer over the principal surface of the semiconductor material body; producing at least one etch window in the dielectric layer; introducing etch stabilizing ions into a portion of the semiconductor material body of the substrate proximate the principal surface and through the etch window in the dielectric layer, the etch stabilizing ions consisting essentially of fluorine ions implanted to a fluorine ion concentration greater than 5E18 ions per cm3; and forming the one or more trenches by etching away at least part of the semiconductor material body of the substrate containing the etch stabilizing ions through the etch window in the dielectric layer, the one or more trenches each comprising a cavity or micro-cavity extending into, but not through the semiconductor material body of the substrate, and having a width between about 500 and 1200 micrometers. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for etching one or more trenches in a substrate, comprising:
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providing a substrate adapted to receive the one or more trenches therein; forming on the substrate a mask layer resistant to etching of the substrate; opening an etch window in the mask layer overlying the desired location of the one or more trenches; introducing fluorine ions into a portion of the substrate comprising a semiconductor material and underlying the etch window such that the portion of the substrate comprising the semiconductor material has a fluorine ion concentration greater than 5E18 per cm3; and forming the one or more trenches by etching at least part of the portion of the substrate comprising the semiconductor material, underlying the etch window, and containing the fluorine ions, the one or more trenches each comprising a cavity or micro-cavity having a width between about 100 and 2000 micrometers and a depth between about 2 and about 50 micrometers. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
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16. A method for forming a trench in a principle surface of a silicon wafer, comprising:
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forming a dielectric layer over the principal surface of the silicon wafer; producing an etch window in the dielectric layer; implanting fluorine ions through the etch window and into a silicon-comprising portion of the silicon wafer proximate the principal surface; and forming the trench by locally etching through the etch window the silicon-comprising portion of the silicon wafer containing the fluorine ions using tetra-methyl-ammonium hydroxide (TMAH), the trench comprising a cavity or micro-cavity extending into, but not through the silicon wafer; wherein the etching step comprises at least two silicon etching steps separated by one or more cleaning steps. - View Dependent Claims (17)
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Specification