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US 8,045,142 B2Granted
Polishing end point detection method, polishing end point detection apparatus and polishing apparatus
AssigneeEbara Corporation
InventorToshifumi Kimba
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AssigneeEbara Corporation
InventorToshifumi Kimba
Estimating the term…
A polishing end point detection method is to detect a polishing end point of a workpiece having a multilayer structure. The method is performed by emitting a first light and a second light to a surface of the workpiece at a first angle of incidence and a second angle of incidence, respectively, receiving the first light and the second light reflected from the surface through a polarizing filter, performing a first analyzing process of analyzing a brightness and a saturation of the surface from the first light received, performing a second analyzing process of analyzing a brightness and a saturation of the surface from the second light received, and determining removal of the upper layer based on changes in the brightness and the saturation of the surface.
A method of detecting a polishing end point of a workpiece having an upper layer and an underlying lower layer, said method comprising:
An apparatus for detecting a polishing end point of a workpiece having an upper layer and an underlying lower layer, said apparatus comprising:
An apparatus for polishing a workpiece having an upper layer and an underlying lower layer, said apparatus comprising:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
Polarisation-affecting properties: ellipsometry
Control means for lapping machines or devices: devices or means for detecting lapping completion
Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring…
Ellipsometry: brewster incidence arrangement
About 3 years 4 months of term left · ends 8 Mar 2030 (estimated)
1. Field of the Invention
The present invention relates to a polishing end point detection method, a polishing end point detection apparatus, and a polishing apparatus, and more particularly to a polishing end point detection method and a polishing end point detection apparatus for detecting an end point of polishing of a multilayer structure.
2. Description of the Related Art
FIG. 1 is a cross-sectional view showing a process of STI;
FIG. 2 is a view for illustrating a principle of a polishing end point detection according to an embodiment of the present invention;
FIG. 3 is a graph illustrating a reflectance of p-polarized light and a reflectance of s-polarized light that vary depending on an angle of incidence;
Embodiments of the present invention will be described below with reference to the drawings.
The principle of the present invention will now be described with reference to FIG. 2. When a light is incident on an interface between two substances having different indexes of refraction, p-polarized light is not reflected from the interface at a particular angle of incidence. This angle of incidence is called Brewster's angle, which is given by a known formula using the indexes of refraction of the two substances. FIG. 3 is a graph illustrating a reflectance of p-polarized light and a reflectance of s-polarized light that vary depending on the angle of incidence. As shown in FIG. 3, Brewster's angle given by indexes of refraction of air and SiO2 is 55.4 degrees, and Brewster's angle given by indexes of refraction of air and SiN is 63.4 degrees.
In FIG. 2, when the light is incident on the interface at an angle near the Brewster's angle θ, the reflected light is mainly composed of the s-polarized light (this reflected light is denoted by reference numeral 100 in FIG. 2). Part of the incident light passes through a substance (e.g., a film), and is reflected off a surface of an underlayer (this reflected light is denoted by reference numeral 101 in FIG. 2). The reflected light 100 and the reflected light 101 interfere with each other to produce an interference color.