Robust end-point detection for contact and via etching
First Claim
1. A method for improving the end-point detection for contact hole etching in multilayer metallurgy of submicron IC devices comprising the steps of:
- providing a semiconductor substrate having devices formed within its surface;
depositing interconnect metal onto said substrate surface;
patterning local interconnect regions and dummy regions on said substrate;
depositing oxide layer over said substrate and covering said interconnect metal under thereof;
etching contact holes and dummy holes through the thickness of said oxide layer; and
depositing first level metal into contact and dummy holes.
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Accused Products
Abstract
A method for improving the end-point detection for contact and via etching is disclosed. The disclosure describes the deliberate addition of dummy patterns in the form of contact and via holes to the regular functional holes in order to increase the amount of etchable surface area. It is shown that, one can then take advantage of the marked change in the composition of the etchant gas species that occurs as soon as what was once a large exposed area has now been consumed through the etching process. This then gives a strong and robust signal for the end of the etching process. This in turn results in better controlled and more reliable product. It is also indicated that with the full uniform pattern of the via layers now possible, the chemical/mechanical polishing process becomes much less pattern sensitive.
107 Citations
24 Claims
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1. A method for improving the end-point detection for contact hole etching in multilayer metallurgy of submicron IC devices comprising the steps of:
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providing a semiconductor substrate having devices formed within its surface; depositing interconnect metal onto said substrate surface; patterning local interconnect regions and dummy regions on said substrate; depositing oxide layer over said substrate and covering said interconnect metal under thereof; etching contact holes and dummy holes through the thickness of said oxide layer; and depositing first level metal into contact and dummy holes. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method for improving the end-point detection for via hole etching in multilayer metallurgy of submicron IC devices comprising the steps of:
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providing a semiconductor substrate having a first level of metallization on its surface; depositing an oxide coating over said substrate surface; etching via holes and dummy holes through the thickness of said oxide coating; and depositing second level metal into said via and dummy holes. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A method of forming an interconnecting metallization system comprising the steps of:
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providing a semiconductor substrate having devices formed within its surface; depositing interconnect metal layer onto said substrate surface; forming active and dummy metal interconnect regions on said interconnect metal layer; depositing first oxide layer covering said interconnect metal layer on said substrate surface; forming contact holes and dummy contact holes through said first oxide layer, wherein said respective holes reach underlying said active and said dummy interconnect regions, respectively; depositing first level metal; forming active and dummy first metal regions on said first level metal; depositing second oxide layer covering said first level metal on said substrate surface; forming via holes and dummy via holes through said second oxide layer, wherein said respective holes reach underlying said active and said dummy first level metal regions, respectively; depositing second level metal; and depositing passivation layer.
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Specification