EP0539686A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Process for producing metrological structures particularly useful for analyzing the accuracy of instruments for measuring alignment on processed substrates
Assignee: STMicroelectronics SRL
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Filing: 1992-08-25
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Granted: —
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Expires: 2012-08-25
Abstract
Abstract Process for producing metrological structures particularly useful for analyzing the accuracy of instruments for measuring alignment on processed substrates. The process produces metrological structures which have measurement profiles defined on substrate regions and on industrially-processed regions on a single wafer. The measurement profiles define statistical distributions which can be detected by measurement machines in order to analyze the measurement accuracy of the machines themselves.
Inventors
- 👤 Paolo Canestrari
- 👤 Carlo Lietti
- 👤 Giovanni Rivera
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 18:03
CPC Classifications
H; H10; H10P; H10P74/00; H10P74/27; H10P74/277; G; G03; G03F; G03F7/00; G03F7/0035; H10P74/20; H10P74/203
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
379 words
Process for producing metrological structures particularly for analyzing the accuracy of instruments for measuring alignment on processed substrates, characterized in that it comprises the following steps, performed sequentially on a substrate: -- an initial step, during which a first layer of a first material is deposited on said substrate; -- an area definition step, during which a layer of radiation-sensitive material is deposited on said first layer and is masked and developed in order to select regions of said substrate; -- a first etching step, during which the regions of said first material uncovered during said area definition step are etched, the remaining part of said layer of radiation-sensitive material being then removed, defining a plurality of mutually alternating regions on said substrates; -- a first deposition step, during which said regions are simultaneously covered with a deposition of a layer of radiation-sensitive material which is subsequently masked and developed, uncovering insulated regions of said substrate and of said first layer; -- a second etching step, during which said insulated regions of said substrate are etched, defining wells and also partially etching said insulated regions of said first layer; -- a second deposition step, during which said regions are simultaneously covered with the deposition of another layer of radiation-sensitive material which is masked and developed in order to uncover said insulated regions of said first layer; -- a third etching step, during which said insulated regions of said first layer are etched, creating wells, and said radiation-sensitive material is removed; -- a third deposition step, during which a second layer of a second material is deposited on said regions; -- a fourth deposition step, during which a layer of radiation-sensitive material is deposited on said second layer and is then masked and developed, uncovering regions of said second layer at said regions of the substrate; -- a fourth etching step, during which said regions of said second layer are etched, uncovering said regions of said substrate, and said radiation-sensitive material is removed; -- a final step, during which said substrate regions and said second-layer regions are covered with the deposition of a layer of radiation-sensitive material which is masked and developed, obtaining insulated regions of radiation-sensitive material defined at said wells of said substrate and of said first layer.
Claim 2
Dependent Claim
26 words
Process according to claim 1, characterized in that said first material is selectively constituted by polysilicon, by contact dielectric, by a first metalization and by vias.
Claim 3
Dependent Claim
31 words
Process according to the preceding claims, characterized in that said second material is selectively constituted by a layer of contacts, by a first metalization, by vias and by a second metalization.
Claim 4
Dependent Claim
30 words
Process according to claim 1, characterized in that said first material is selectively constituted by a layer of contacts, by a first metallization, by vias and by a second metallization.
Claim 5
Dependent Claim
28 words
Process according to claims 1 and 4, characterized in that said second material is selectively constituted by polysilicon, by contact dielectric, by a first metallization and by vias.
Claim 6
Dependent Claim
412 words
Process for producing metrological structures particularly for analyzing the accuracy of instruments for measuring alignment on processed substrates, characterized in that it comprises the following steps, performed sequentially on a substrate: -- an initial step, during which a first layer of silicon nitride is deposited on said substrate; -- a first deposition step, during which a layer of radiation-sensitive material is deposited on said first layer and is then masked and developed in order to delimit regions of said substrate and of said first layer; -- a first etching step, during which said first layer is etched, uncovering regions of said substrate, and said layer of radiation-sensitive material is subsequently removed; -- a second deposition step, during which a layer of radiation-sensitive material is deposited on the substrate and nitride regions and is subsequently masked and developed, delimiting insulated regions of said substrate and of said first layer; -- a second etching step, during which said substrate is etched, creating wells in said substrate and partially etching said first layer; -- a third deposition step, during which a layer of radiation-sensitive material is deposited on said substrate and first-layer regions and is subsequently masked and developed in order to delimit insulated regions of said first layer; -- a third etching step, during which said insulated regions of said first layer are etched and said radiation-sensitive material is subsequently removed; -- a growth step, during which a second layer of field oxide is grown; -- a fourth etching step, during which said first layer is etched completely; -- a fourth deposition step, during which a layer of radiation-sensitive material is deposited and is subsequently masked and developed, uncovering insulated regions of said second layer; -- a fifth etching step, during which said second layer is etched, uncovering said wells of said substrate, and said radiation-sensitive material is then removed; -- a fifth deposition step, during which a third layer of polysilicon is deposited; -- a sixth deposition step, during which a layer of radiation-sensitive material is deposited on said third layer and is subsequently masked and developed in order to delimit said regions of said substrate; -- a sixth etching step, during which said third layer is etched, uncovering said regions of said substrate, and said radiation-sensitive material is subsequently removed; -- a final step, during which a layer of radiation-sensitive material is deposited and subsequently masked and developed, delimiting insulated regions of radiation-sensitive material on said substrate and on said third layer.
Claim 7
Dependent Claim
21 words
Process according to one or more of the preceding claims, characterized in that said substrate is constituted by a silicon wafer.
Claim 8
Dependent Claim
52 words
Process according to one or more of the preceding claims, characterized in that statistical distributions of photoresist insulated regions are defined on said silicon wafer on substrate regions and on industrially processed regions, said distributions being suitable for being measured and compared to one another for the calibration of alignment measurement machines.
References Cited (Backward Citations)
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