Patterned wafer inspection method and apparatus therefor

• US 20040222377A1
• Filed: 06/14/2004
• Published: 11/11/2004
• Est. Priority Date: 10/02/1997
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Umemura, Kaoru, Nozoe, Mari, Yajima, Yusuke, Hasegawa, Masaki, Sugiyama, Katsuya, Usami, Yasutsugu, Kuroda, Katsuhiro, Takafuji, Atsuko, Murakoshi, Hisaya, Shinada, Hiroyuki
• Granted Patent: US 6,979,823 B2
• Time in Patent Office: Days
• US Class Current: 250/310
• CPC Class Codes: G01N 23/225 using electron or ion
• CPC Class Codes: H01J 2237/20228 Mechanical X-Y scanning
• CPC Class Codes: H01J 2237/221 Image processing
• CPC Class Codes: H01J 2237/2447 Imaging plates
• CPC Class Codes: H01J 2237/24475 Scattered electron detectors
• CPC Class Codes: H01J 2237/24485 Energy spectrometers
• CPC Class Codes: H01J 2237/24592 Inspection and quality control of devices
• CPC Class Codes: H01J 2237/2482 Optical means
• CPC Class Codes: H01J 37/244 Detectors; Associated components or circuits therefor
• CPC Class Codes: H01J 37/26 Electron or ion microscopes; Electron or ion diffraction tubes
• CPC Class Codes: H01J 37/29 Reflection microscopes

Abstract

An electron beam (area beam) having a fixed area is irradiated onto the surface of a semiconductor sample, and reflected electrons from the sample surface are imaged by the imaging lens, and images of a plurality of regions of the surface of the semiconductor sample are obtained and stored in the image storage unit, and the stored images of the plurality of regions are compared with each other, and the existence of a defect in the regions and the defect position are measured. By doing this, in an apparatus for testing a pattern defect of the same design, foreign substances, and residuals on a wafer in the manufacturing process of a semiconductor apparatus by an electron beam, speeding-up of the test can be realized.

Claims

1-41. -41. (Canceled)

42. A sample inspection apparatus comprising:

a sample stage to hold a wafer to be inspected, an electron optical system to irradiate an electron beam to the sample,

a power source connected to the sample stage,

an image detector that detects the reflected electron and creates a image signal based on the detected electron, and

an image processor that inspects the sample by comparing obtained images,

wherein said power source applies a potential to the sample stage so that the irradiated electron is reflected before the irradiated electron beam reaches a surface of the sample.

44. A sample inspection apparatus, according to claim 42, wherein,

said electron optical system irradiates an area electron beam to the sample.

45. A sample inspection apparatus, according to claim 42, wherein, said image detector is comprised of TDI sensor.

46. A sample inspection apparatus, according to claim 42, said electron optical system further comprising:

a schottky type electron source.

43. A sample inspection apparatus comprising:

means for holding a sample to be inspected,

means for irradiating an electron beam to the sample,

means for reflecting the electron beam irradiated to the sample before the electron beam reaches a surface of the sample,

means for detecting the reflected electrons,

means for creating an image attributed to the reflected electrons, and

means for inspecting the sample by comparing obtained images.

47. A sample defect inspection apparatus comprising:

an electron optic system to irradiate an area electron beam to a sample to be inspected,

a power source to apply a predetermined voltage to a sample to be inspected, and

an electron detector to detect the reflected electron from a sample to be inspected, an image processor, wherein

the irradiated electron beam is substantially reflected just before reaching a surface of a sample to be inspected, and

said image processing unit forms an image of a sample to be inspected and analyzes the image to detect a defect in a sample to be inspected.

48. A sample inspection apparatus comprising:

a sample stage to hold a wafer to be inspected,

an electron optical system to irradiate an electron beam to the sample,

a power source that gives a potential to the sample,

an image detector that detects an electrons reflected from the sample before the irradiated electron beam reaches a surface of the sample,

an image processor that inspects the sample by comparing image signals obtained in the image detector.

49. A sample inspection apparatus comprising:

a sample stage to hold a wafer to be inspected,

an electron optical system to irradiate an electron beam to the sample,

a power source that gives a potential to the sample,

an image detector that creates an image signal based on detection of an electron which is reflected from the sample before the irradiated electron beam reaches a surface of the sample, and

an image processor that inspects the sample by comparing obtained images.

50. A sample inspection apparatus comprising:

means for holding a sample to be inspected,

means for decelerating an irradiated electron beam before the sample,

means for detecting the reflected electrons turned before impinging on the sample,

means for creating an image attributed to the reflected electrons, and

means for inspecting the sample by comparing obtained images.