Plasma etch process
First Claim
1. In a method for plasma etching a SiOx material comprising(a) establishing a plasma in a vacuum container in a confined region between two closely displaced planar electrodes by providing a flow of reactive gases to said confined region and RF power at a frequency on the order of 400 KHz across said electrodes,(b) fastening said SiOx material to be etched to one of said electrodes,The Improvement Comprising,said reaction gases including CHF3,cooling said plasma by inelastic collisions, andselecting the said flow of gases to obtain a total chamber pressure, p, where 10.0 Torr>
- p>
1.5 Torr wherein said step of cooling includes causing a high volume flow rate of light mass gas to be included in said reaction gases, which flow rate of said light mass gas is approximately 50-100 times greater than the flow rate of CHF3, wherein said light mass gas comprises Helium.
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Accused Products
Abstract
An improved SiOx etch which employs CHF3, N2 and a light mass cooling gas in total pressure on the order of 3000 mT in a confined plasma reactor. High aspect ratios at least 10:1 are obtainable.
24 Citations
12 Claims
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1. In a method for plasma etching a SiOx material comprising
(a) establishing a plasma in a vacuum container in a confined region between two closely displaced planar electrodes by providing a flow of reactive gases to said confined region and RF power at a frequency on the order of 400 KHz across said electrodes, (b) fastening said SiOx material to be etched to one of said electrodes, The Improvement Comprising,said reaction gases including CHF3, cooling said plasma by inelastic collisions, andselecting the said flow of gases to obtain a total chamber pressure, p, where 10.0 Torr>- p>
1.5 Torr wherein said step of cooling includes causing a high volume flow rate of light mass gas to be included in said reaction gases, which flow rate of said light mass gas is approximately 50-100 times greater than the flow rate of CHF3, wherein said light mass gas comprises Helium. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- p>
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10. In a method for producing interlayer metal interconnects in an integrated circuit having metal interconnect strips thereon, comprising:
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(a) applying a TiN layer over the top of said metal interconnect strips; (b) applying a dielectric fill over said TiN coated metal interconnect strips; (c) planarizing the top of said dielectric fill; (d) applying and patterning a resist mask over the top of said metal interconnect strips; (e) placing said patterned wafer into a confined plasma etch reactor and fastening said wafer onto an electrode of said reactor; (f) introducing reaction gases, said reaction gases comprising CHF3, N2 and a light mass cooling gas into said confined plasma etch reactor; (g) exciting said plasma by applying RF energy at approximately 400 KHz, wherein the said light mass cooling gas composes He and the He volume flow is 50 -100 times greater than the volume flow rate of either CHF3 or N2 and the total flow is adjusted to establish a high pressure p where 10.0 Torr>
p>
1.5 Torr. - View Dependent Claims (11, 12)
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Specification