Electron beam apparatus
The present invention includes an electron beam device for examining defects on semiconductor devices. The device includes an electron source for generating a primary electron beam, wherein the total acceleration potential is divided and is provided across the ground potential. Also included is at least one condenser lens for pre-focusing the primary electron beam, an aperture for confining the primary electron beam to ameliorate electron-electron interaction, wherein the aperture is positioned right underneath the last condenser lens, and a SORIL objective lens system for forming immersion magnetic field and electrostatic field to focus the primary beam onto the specimen in the electron beam path. A pair of grounding rings for providing virtual ground voltage potential to those components within the electron beam apparatus installed below a source anode and above a last polepiece of the SORIL objective lens.
1. An electron beam apparatus for examining defects on a semiconductor wafer device, the apparatus comprising:
an electron source for generating a primary electron beam, wherein the total acceleration potential is divided and is provided across the ground potential;
at least one condenser lens for pre-focusing the primary electron beam;
an aperture for confining the primary electron beam to ameliorate electron-electron interaction, wherein the aperture is positioned right underneath the last condenser lens;
a SORIL objective lens system for forming immersion magnetic field and electrostatic field to focus the primary beam onto the specimen in the electron beam path;
a pair of grounding rings for providing virtual a ground voltage potential to those components within the electron beam apparatus installed below a source anode and above a last polepiece of the SORIL objective lens;
at least one pair of deflectors for deflecting the primary electron beam over the specimen surface to form a scanning pattern;
a detection system for detecting signal electrons; and
a stage to hold the specimen to be inspected.
2. The electron beam apparatus according to claim 1 , wherein the electron source is a Schottky emitter that includes a cathode and an anode, wherein there is no extractor between a cathode and an anode, and wherein the electron beam acceleration voltage potential is applied across the cathode and the anode, the SORIL objective lens system.
3. The electron beam apparatus in accordance to claim 1 , wherein the detection system comprises scintillator-photomultiplier detectors.
4. The electron beam apparatus according to claim 3 , wherein the scintillator-photomultiplier detector is on a voltage potential between zero volt and 10,000 volt.
5. The electron beam apparatus according to claim 1 , wherein the stage is also applied to a voltage potential to achieve varied electron landing energy.
6. The electron beam apparatus according to claim 5 , wherein the landing energy of the electron beam is chosen between 0 volt and 8,000 volt.
7. An electron bean apparatus for examining a semiconductor device, the apparatus comprising:
an electron source for generating a primary electron beam, wherein the total acceleration potential is divided and across the ground potential;
a beam elevator for electron beam traveling in an elevate voltage versus ground potential to minimize Boersch effect;
at least one condenser lens for pre-focusing the primary electron beam;
an aperture for confining the primary electron beam to ameliorate electron-electron interaction, wherein the aperture is positioned right underneath the last condenser lens;
a SORIL objective lens system for forming immersion magnetic field and electrostatic field to focus the primary beam onto the specimen in the electron beam path;
a pair of grounding rings for providing a virtual ground voltage potential to those components within the electron beam apparatus installed below the aperture and above a last polepiece of the SORIL objective lens;
at least one pair of deflector for deflecting the primary electron beam over the specimen surface to form a scanning pattern;
a detection system for detecting signal electrons; and
a stage to hold the specimen to be inspected.
8. The electron beam apparatus according to claim 7 , wherein the electron source is a Schottky emitter includes a cathode and an anode, wherein no extractor between the cathode and the anode, wherein the electron beam acceleration voltage potential is applied across the cathode and the anode.
9. The electron beam apparatus according to claim 7 , wherein the beam elevator holds a constant voltage potential, and wherein the voltage potential applied is between 5,000 volt and 20,000 volt.
10. The electron beam apparatus according to claim 7 , wherein the stage is also applied to a voltage potential to achieve varied electron landing energy.
11. The electron beam apparatus according to claim 10 , wherein the landing energy of the electron beam is chosen between 0 volt and 8,000 volt.