US5784167A
Expired / Lapsed
US
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Method of measuring thickness of a multi-layers film
Assignee: United Microelectronics Corp
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Filing: 1996-12-03
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Granted: 1998-07-21
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Expires: 2016-12-03
Abstract
Abstract A multi-layers with (m+1) sublayers is formed on a substrate. The purpose of the present invention is to measure the thickness of the sublayer (m+1) using the ellipsometry even the physical parameters of the other sublayers are unknow. The key of the method is to reguard the multi-layers (sublayer 1/sublayer 2/ . . . /sublayer m) as a reduced layer. Then the multi-layers becomes a double layers formed on a substrate, that is a sublayer (m+1) and a reduced layer. Assume that the sublayer (m+1) is composed of material M. Then the multi-layers becomes a double M layers formed on a substrate, that is a M layer and a reduced layer. A first measurement is performed to measure the thickness (T1) of the double layers by using an ellipsometry. Next, a second measurement is done to measure the thickness (T2) of the reduced layer by using an ellipsometry. The thickness of the sublayer (m+1) can be obtained by performing (T1-T2).
Inventors
- 👤 Chao-Huang Ho
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:37
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/02; G01B11/06; G01B11/0616; G01B11/0641; G01B11/065
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
159 words
A method of measuring an actual thickness of a top layer of some material on the top of a multi-layers having at least three sublayers formed on a substrate, the other sublayers are not made of said material of said top layer, said method comprising the steps of: assuming all of the layers in said multi-layer being made of said material of said top layer; performing a first measurement to said multi-layers by using an ellipsometry to obtain a first fictional pseudo-thickness of said multi-layers; stripping said top layer to form a reduced layer consisting of said other sublayers; assuming said reduced layer being made of said material of said top layer; performing a second measurement to said reduced layer by using said ellipsometry to obtain a second fictional pseudo-thickness of said reduced layer; and obtaining said actual thickness of said top layer, said actual thickness being the difference of said first fictional pseudo-thickness and said second fictional pseudo-thickness.
Claim 2
Independent Claim
159 words
A method of measuring an actual thickness of a top layer of some material on the top of a multi-layers having at least three sublayers formed on a substrate, the other sublayers are not made of said material of said top layer, said method comprising the steps of: assuming all of the layers in said multi-layer being made of said material of said top layer; performing a first measurement to said multi-layers by using an ellipsometry to obtain a first fictional pseudo-thickness of said multi-layers; stripping said top layer to form a reduced layer consisting of said other sublayers; assuming said reduced layer being made of said material of said top layer; performing a second measurement to said reduced layer by using said ellipsometry to obtain a second fictional pseudo-thickness of said reduced layer; and obtaining said actual thickness of said top layer, said actual thickness being the difference of said first fictional pseudo-thickness and said second fictional pseudo-thickness.
Claim 3
Independent Claim
213 words
A method of measuring an actual thickness of a (m+1)th sublayer of a multi-layers having (m+1) sublayers which is formed on a substrate, said multi-layers and said substrate are formed of substrate/sublayer 1/sublayer 2/sublayer 3/ . . . /sublayer m/sublayer (m+1), m=1, 2, 3, . . . postive integer, said (m+1)th sublayer is a top layer of some material on the top of said multi-layers, the other sublayers are not made of said material of said top layer, said method comprising the steps of: assuming all of the layers in said multi-layer being made of said material of said top layer; performing a first measurement to said multi-layers consisting of sublayer 1/sublayer 2/sublayer 3/ . . . /sublayer m/sublayer (m+1) by using an ellipsometry to obtain a first fictional pseudo-thickness of said multi-layers; stripping said top layer to form a reduced layer consisting of sublayer 1/sublayer 2/sublayer 3/ . . . /sublayer m; assuming said reduced layer being made of said material of said top layer; performing a second measurement to said reduced layer by using said ellipsometry to obtain a second fictional pseudo-thickness of said reduced layer; and obtaining said actual thickness of said top layer, said actual thickness being the difference of said first fictional pseudo-thickness and said second fictional pseudo-thickness.
Claim 4
Independent Claim
213 words
A method of measuring an actual thickness of a (m+1)th sublayer of a multi-layers having (m+1) sublayers which is formed on a substrate, said multi-layers and said substrate are formed of substrate/sublayer 1/sublayer 2/sublayer 3/ . . . /sublayer m/sublayer (m+1), m=1, 2, 3, . . . postive integer, said (m+1)th sublayer is a top layer of some material on the top of said multi-layers, the other sublayers are not made of said material of said top layer, said method comprising the steps of: assuming all of the layers in said multi-layer being made of said material of said top layer; performing a first measurement to said multi-layers consisting of sublayer 1/sublayer 2/sublayer 3/ . . . /sublayer m/sublayer (m+1) by using an ellipsometry to obtain a first fictional pseudo-thickness of said multi-layers; stripping said top layer to form a reduced layer consisting of sublayer 1/sublayer 2/sublayer 3/ . . . /sublayer m; assuming said reduced layer being made of said material of said top layer; performing a second measurement to said reduced layer by using said ellipsometry to obtain a second fictional pseudo-thickness of said reduced layer; and obtaining said actual thickness of said top layer, said actual thickness being the difference of said first fictional pseudo-thickness and said second fictional pseudo-thickness.
Claim 5
Independent Claim
171 words
A method of measuring an actual thickness of a top layer of some material on the top of a first multi-layers having at least three sublayers, the other sublayers are not made of said material of said top layer, said method comprising the steps of: forming a second multi-layers consisting of said other sublayers on a substrate; assuming all of the layers of said second multi-layer being made of said material of said top layer; performing a first measurement to said second multi-layers by using an ellipsometry to obtain a first fictional pseudo-thickness of said first multi-layers; forming said top layer on said second multi-layers to form a first multi-layers; assuming said second multi-layer being made of said material of said top layer; performing a second measurement to said first multi-layers layer by using said ellipsometry to obtain a second fictional pseudo-thickness of said second multi-layers; and obtaining said actual thickness of said top layer, said actual thickness being the difference of said first fictional pseudo-thickness and said second fictional pseudo-thickness.
Claim 6
Independent Claim
171 words
A method of measuring an actual thickness of a top layer of some material on the top of a first multi-layers having at least three sublayers, the other sublayers are not made of said material of said top layer, said method comprising the steps of: forming a second multi-layers consisting of said other sublayers on a substrate; assuming all of the layers of said second multi-layer being made of said material of said top layer; performing a first measurement to said second multi-layers by using an ellipsometry to obtain a first fictional pseudo-thickness of said first multi-layers; forming said top layer on said second multi-layers to form a first multi-layers; assuming said second multi-layer being made of said material of said top layer; performing a second measurement to said first multi-layers layer by using said ellipsometry to obtain a second fictional pseudo-thickness of said second multi-layers; and obtaining said actual thickness of said top layer, said actual thickness being the difference of said first fictional pseudo-thickness and said second fictional pseudo-thickness.
Claim 7
Independent Claim
242 words
A method of measuring an actual thickness of a (m+1)th sublayer of a multi-layers having (m+1) sublayers, said multi-layers and substrate are formed of substrate/sublayer 1/sublayer 2/sublayer 3/ . . . /sublayer m/sublayer (m+1), m=1, 2, 3, . . . said (m+1)th sublayer is a top layer of some material on the top of said multi-layers, the other sublayers are not made of said material of said top layer, said method comprising the steps of: forming a first multi-layers on a substrate, said first multi-layers and said substrate are formed of substrate/sublayer 1/sublayer 2/sublayer 3/ . . . /sublayer m/sublayer (m +1), m=1, 2, 3, . . . postive integer; assuming all of the layers of said first multi-layer being made of said material of said top layer; performing a first measurement to said first multi-layers (sublayer 1/sublayer 2/sublayer 3/ . . . /sublayer m/sublayer (m+1)) by using an ellipsometry to obtain a first fictional pseude-thickness of said first multi-layers; forming a sublayer (m+1) on said sublayer m to form a second multi-layers (sublayer 1/sublayer 2/sublayer 3/ . . . /sublayer m); assuming said second multi-layer being made of said material of said top layer; performing a second measurement to said second multi-layers by using said ellipsometry to obtain a second fictional pseude-thickness of said second multi-layers; and obtaining said actual thickness of said top layer, said actual thickness being the difference of said first fictional pseudo-thickness and said second fictional pseudo-thickness.
Claim 8
Independent Claim
242 words
A method of measuring an actual thickness of a (m+1)th sublayer of a multi-layers having (m+1) sublayers, said multi-layers and substrate are formed of substrate/sublayer 1/sublayer 2/sublayer 3/ . . . /sublayer m/sublayer (m+1), m=1, 2, 3, . . . said (m+1)th sublayer is a top layer of some material on the top of said multi-layers, the other sublayers are not made of said material of said top layer, said method comprising the steps of: forming a first multi-layers on a substrate, said first multi-layers and said substrate are formed of substrate/sublayer 1/sublayer 2/sublayer 3/ . . . /sublayer m/sublayer (m +1), m=1, 2, 3, . . . postive integer; assuming all of the layers of said first multi-layer being made of said material of said top layer; performing a first measurement to said first multi-layers (sublayer 1/sublayer 2/sublayer 3/ . . . /sublayer m/sublayer (m+1)) by using an ellipsometry to obtain a first fictional pseude-thickness of said first multi-layers; forming a sublayer (m+1) on said sublayer m to form a second multi-layers (sublayer 1/sublayer 2/sublayer 3/ . . . /sublayer m); assuming said second multi-layer being made of said material of said top layer; performing a second measurement to said second multi-layers by using said ellipsometry to obtain a second fictional pseude-thickness of said second multi-layers; and obtaining said actual thickness of said top layer, said actual thickness being the difference of said first fictional pseudo-thickness and said second fictional pseudo-thickness.
References Cited (Backward Citations)
US4906844A
Cited
US5420680A
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