OPTICAL INSPECTION METHOD AND OPTICAL INSPECTION APPARATUS

• US 20120273660A1
• Filed: 07/09/2012
• Published: 11/01/2012
• Est. Priority Date: 06/30/2006
• Status: Active Grant

• Current Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Original Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Inventors: MATSUI, Shigeru
• Granted Patent: US 8,878,119 B2
• Time in Patent Office: Days
• US Class Current: 250/214.A
• CPC Class Codes: G01N 21/94 Investigating contamination, e.g. dust G01N21/85 takes precedence
• CPC Class Codes: G01N 21/9501 Semiconductor wafers manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10

Abstract

In the conventional contaminant particle/defect inspection method, if the illuminance of the illumination beam is held at not more than a predetermined upper limit value not to give thermal damage to the sample, the detection sensitivity and the inspection speed being in the tradeoff relation with each other, it is very difficult to improve one of the detection sensitivity and the inspection speed without sacrificing the other or improve both at the same time. The invention provides an improved optical inspection method and an improved optical inspection apparatus, in which a pulse laser is used as a light source, and a laser beam flux is split into a plurality of laser beam fluxes which are given different time delay to form a plurality of illumination spots. The scattered light signal from each illumination spot is isolated and detected by using a light emission start timing signal for each illumination spot.

Claims

1-38. -38. (canceled)

39. A detection apparatus comprising:

a detection unit which receives pulse light, and outputs a detection signal;

a switching unit which executes switching as a function of a photoelectric conversion signal, and outputs said detection signal, wherein;

said switching unit is configured to use said photoelectric conversion signal as input for said switching, and

said photoelectric conversion signal corresponds to emission of said pulse light.

40. The detection apparatus according to claim 39, further comprising:

a wave generating unit which generates a delay signal,

wherein said switching unit is configured to use said delay signal as further input for said switching.

41. The detection apparatus according to claim 39, further comprising:

a wave generating unit which generates a continuation signal,

wherein said switching unit is configured to use said continuation signal as further input for said switching.

42. The detection apparatus according to claim 39, wherein said switching unit includes at least one of a gate circuit, and an integral circuit.

43. The detection apparatus according to claim 39, further comprising:

a first amplifier which amplifies said detection signal, and outputs a first amplified signal to said switching unit.

44. The detection apparatus according to claim 43, further comprising:

a second amplifier which amplifies said first amplified signal, and outputs a second amplified signal.

45. A switching apparatus comprising:

a switching unit which executes switching as a function of a photoelectric conversion signal, and outputs a signal, wherein;

said switching unit is configured to use said photoelectric conversion signal as input for said switching, and

said photoelectric conversion signal corresponds to emission of a pulse light.

46. The switching apparatus according to claim 45, further comprising:

a wave generating unit which generates a delay signal,

wherein said switching unit configured to use said delay signal as further input for said switching.

47. The switching apparatus to claim 45, further comprising:

a wave generating unit which generates a continuous signal,

wherein said switching unit is configured to use said continuous signal as further input for said switching.

48. The switching apparatus to claim 45, wherein said switching unit includes at least one of a gate circuit, and an integral circuit.

49. The switching apparatus according to claim 45, further comprising:

a first amplifier which amplifiers said detection signal, and outputs a first amplified signal to said switching unit.

50. The switching apparatus according to claim 49, further comprising:

a second amplifier which amplifies said first amplified signal, and outputs a second amplified signal.