Electrical process monitoring using mirror-mode electron microscopy
First Claim
Patent Images
1. A method of inspecting a substrate using electrons, the method comprising:
- obtaining multiple images of a region of the substrate using mirror-mode electron-beam imaging at a range of voltage differences between an electron source and a substrate, each said image corresponding to one said voltage difference;
storing image data corresponding to the multiple voltage differences; and
calculating a measure of variation of an imaged aspect of a feature in the region with respect to the voltage difference between the electron source and the substrate,wherein the method provides sub-volt voltage contrast between said images without needing to use an energy-filter with sub-volt resolution.
1 Assignment
0 Petitions
Accused Products
Abstract
One embodiment relates to a method of inspecting a substrate using electrons. Mirror-mode electron-beam imaging is performed on a region of the substrate at multiple voltage differences between an electron source and a substrate, and image data is stored corresponding to the multiple voltage differences. A calculation is made of a measure of variation of an imaged aspect of a feature in the region with respect to the voltage difference between the electron source and the substrate. Other embodiments and features are also disclosed.
107 Citations
32 Claims
-
1. A method of inspecting a substrate using electrons, the method comprising:
-
obtaining multiple images of a region of the substrate using mirror-mode electron-beam imaging at a range of voltage differences between an electron source and a substrate, each said image corresponding to one said voltage difference; storing image data corresponding to the multiple voltage differences; and calculating a measure of variation of an imaged aspect of a feature in the region with respect to the voltage difference between the electron source and the substrate, wherein the method provides sub-volt voltage contrast between said images without needing to use an energy-filter with sub-volt resolution. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. An apparatus comprising:
-
an electron beam instrument configured for obtaining multiple images of a region of the substrate using mirror-mode electron beam imaging at a range of voltage differences between an electron source and a substrate, each said image corresponding to one said voltage difference; a data processing system configured to store image data corresponding to the multiple voltage differences; and processor-executable code configured to calculating a measure of variation of an imaged aspect of a feature in the region with respect to the voltage difference between the electron source and the substrate, wherein the apparatus provides sub-volt voltage contrast between said images without needing to use an energy filter with sub-volt resolution. - View Dependent Claims (14, 15, 16, 17, 18)
-
-
19. An apparatus for inspecting a substrate using a projection electron beam system, the apparatus comprising:
-
an illumination subsystem configured to generate an incident electron beam; an objective subsystem configured to receive the incident electron beam, to focus the incident electron beam onto a region of the substrate, and to retrieve a scattered beam from the substrate; a projection subsystem configured to receive the scattered beam and to project the scattered beam onto a detector so as to detect electron images of the region; and a beam separator coupled to and interconnecting the illumination subsystem, the objective subsystem, and the projection subsystem, wherein the beam separator is configured to receive the incident beam from the illumination subsystem, bend the incident electron beam towards the objective subsystem, receive the scattered beam from the objective subsystem, and bend the scattered beam towards the projection subsystem, and a control system configured to vary a potential difference between a source of the incident electron beam and the substrate, wherein the electron images are obtained of using mirror-mode electron-beam imaging at a range potential differences between the source and the substrate, each said image corresponding to one said potential difference, and further wherein the apparatus provides sub-volt voltage contrast between said images without needing to use an energy-filter with sub-volt resolution. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
-
-
30. A method of inspecting a substrate using electrons, the method comprising:
-
obtaining multiple images of a region of the substrate using mirror-mode electron-beam imaging at a range of voltage differences between an electron source and a substrate, each said image corresponding to one said voltage difference; storing mirror-mode image data corresponding to the multiple voltage differences; scattered electron imaging of the region; storing the scattered electron image data; and comparing gray levels of a feature in the region in the mirror-mode image data to the scattered electron image data of the feature, wherein the method provides sub-volt voltage contrast between said images without needing to use an energy-filter with sub-volt resolution. - View Dependent Claims (31, 32)
-
Specification