JPH042140A - Pattern comparing inspector - Google Patents

Abstract

PURPOSE:To enable the pattern comparing inspector of an arbitrary chip on a wafer with no restrictions in the mechanical movable range of two optical systems by imaging different chips through one optical systems one after another to a wafer made up of a substrate with a plurality of the same patterns and by comparing different chip patterns. CONSTITUTION:While a stage is transferred, the imaging signal of the first chip subjected to comparing inspection is fed from a pattern imaging controller 4 to a pattern imaging recorder 5 and recorded. Further, the stage is transferred to the second chip subjected to comparing inspection, and the imaging signal of the second chip is fed to the pattern imaging controller 4 while the stage is transferred as in the case of the first chip. The imaging signal of the second chip is fed from the pattern imaging controller 4 to a defect detection controller 6 by correction of gain, and the imaging signal of the first chip is fed to the defect detection controller 6. The signals of two chip patterns fed from the defect detection controller 6 are compared and fed to a CPU 7 by detection of defects from comparing inspection with independent defect detection circuits for vertical pattern, lateral pattern, oblique pattern, and corners.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pattern comparison inspection device for wafers of semiconductor devices.

[Prior Art] As shown in FIG. 2, a conventional pattern comparison inspection device
Infrared light emitted from a light source 9 is sent to the light emitting unit optical system 1 via an optical fiber cable. The light emitting unit optical system 1 is arranged under the wafer, and one optical system is fixed and the other optical system is movable in the X direction according to the chip size of the wafer to be inspected. The infrared light that has passed through the light emitting optical system 1 roughly passes through the wafer 8 and enters the light receiving optical system 2. The light-receiving optical system 2 is arranged on the wafer 8, and similarly to the light-emitting optical system 1, one optical system is fixed, and the other optical system is set according to the chip size of the wafer 8 to be inspected.
It is configured to be movable in the X direction.

The infrared light that has passed through the two light receiving optical systems 2 is received by each CCD image sensor 3, and the infrared light that has passed through the wafer is photoelectrically converted into an imaging signal of the wafer pattern. The imaging signals are sent from the CCD image sensor 3 to the pattern imaging control section 4, and the gain of each imaging signal is corrected. Signals from the two pattern imaging control sections 4 are sent to the defect detection control section 6, chip patterns within the wafer are compared and inspected, and defect detection data is sent to the CPU 7. The CPtJ7 controls the device and records the number of defects and the X and Y coordinates of each defect as defect information for the defect detection control section 6.

[Problems to be Solved by the Invention] However, the conventional technology has the problem that it is not possible to perform pattern comparison inspection of arbitrary chips on a wafer due to limitations in the mechanical movable range of the two optical systems. Ta. SUMMARY OF THE INVENTION The present invention is intended to solve these problems, and its purpose is to provide a pattern comparison inspection apparatus capable of pattern comparison inspection of any chip on a wafer.

[Means for Solving the Problems] The pattern comparison inspection device of the present invention includes an optical system that irradiates a wafer with infrared light, and a detection system that photoelectrically converts the transmitted pattern light from the optical system and includes a CCD image sensor. and,
A pattern imaging control unit that controls pattern imaging signals from the detection system; a pattern imaging recording unit that records the output of the pattern imaging control unit; a defect detection control unit that compares data of different chip patterns; and a defect detection control unit that controls the entire device. It also includes a central processing unit that records defect information of the defect detection control unit, and sequentially images different chips using one optical system on a wafer on which multiple identical patterns are formed on one substrate, and detects different chips. A pattern comparison inspection device that compares and inspects patterns.

[Embodiment] FIG. 1 is a block diagram of an embodiment of the present invention, in which infrared light emitted from a light source 9 is sent to a light emitting unit optical system 1 via an optical fiber cable.

The light emitting optical system 1 is arranged under the wafer, and the infrared light is irradiated toward the wafer 8 and transmitted through the parts of the wafer 8 other than the wafer pattern, such as high melting point metals and aluminum (AL), and then the infrared light is transmitted to the light receiving optical system 2. Enter. The light receiving optical system 2 is placed on the wafer 8 at a position where the optical axes are aligned in order to receive the infrared light from the light emitting optical system 1. The infrared light that has passed through the light receiving optical system 2 is received by the CCD image sensor 3, and the infrared light that has passed through the wafer is photoelectrically converted into an imaging signal of the wafer pattern. The imaging signal is sent from the CCD image sensor 3 to the pattern imaging control section 4, and f! Correct the signal gain. While moving the stage, the imaging signal of the first chip to be comparatively inspected is sent from the pattern imaging control section 4 to the pattern imaging recording section 5 and recorded. Furthermore, the stage is moved to the second chip to be compared and inspected, and the imaging signal of the second chip is sent to the pattern imaging control section 4 while moving the stage in the same manner as for the first chip. The pattern imaging control section 4 corrects the gain of the imaging signal of the second chip and sends it to the defect detection control section 6, and also sends the imaging signal of the first chip to the defect detection control section 6. Defects are detected by comparing the signals between the two chip patterns sent to the defect detection control unit 6 and performing comparative inspection using independent defect detection circuits for each of vertical patterns, horizontal patterns, diagonal patterns, corner parts, etc. and is sent to the CPU 7. The CPU 7 controls the apparatus and records the number of defects and the X and Y coordinates of each defect as defect information for the defect detection control section 6.

[Effects of the Invention] According to the invention described above, in defect inspection of patterns of high-melting point metals, AL, etc. on a wafer, it is possible to detect defects on the wafer without being limited in the mechanical movable range of the two optical systems. This has the effect of enabling pattern comparison inspection of any chip.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a pattern defect inspection apparatus of the present invention. FIG. 2 is a configuration diagram showing a conventional pattern defect inspection device. Emitter Optical System Light Receiver Optical System COD Image Sensor Pattern Imaging Control Unit Pattern Imaging Recording Unit Defect Detection Control Unit PU Wafer Light Source and More Applicant Seiko Epson Corporation Representative Patent Attorney Kizobe Suzuki (1 person in chemical engineering) 1X1

Claims (1)

[Claims] an optical system that irradiates the wafer with infrared light; a detection system that photoelectrically converts the pattern light transmitted by the optical system and includes a CCD image sensor; and a pattern imaging control unit that controls pattern imaging signals from the detection system. a pattern imaging recording section that records the output of the pattern imaging control section; a defect detection control section that compares data of different chip patterns; and a central processing unit that controls the entire device and records defect information of the defect detection control section. A pattern comparison inspection apparatus comprising: a wafer having a plurality of identical patterns formed on one substrate; a single optical system sequentially images different chips; and compares and inspects different chip patterns.