Pattern inspection method and its apparatus

• US 8,090,187 B2
• Filed: 03/16/2010
• Issued: 01/03/2012
• Est. Priority Date: 01/30/2002
• Status: Expired due to Term

• Current Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.), Hitachi, Ltd.
• Original Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.), Hitachi, Ltd.
• Inventors: Sakai, Kaoru, Maeda, Shunji, Okabe, Takafumi, Goto, Hiroshi, Kuwabara, Masayuki, Takeuchi, Naoya
• Primary Examiner(s): Akhavannik, Hadi
• Application Number:
  US12/725,040
• Publication Number:
  US 20100172570A1
• Time in Patent Office: 658 Days
• Field of Search: 382/151, 382144-145, 382/141, 382/294
• US Class Current: 382/141
• CPC Class Codes: G06T 2207/30148 Semiconductor; IC; Wafer
• CPC Class Codes: G06T 7/0002 Inspection of images, e.g. flaw detection
• CPC Class Codes: G06T 7/001 using an image reference approach
• CPC Class Codes: G06T 7/32 using correlation-based methods
• CPC Class Codes: G06T 7/33 using feature-based methods

Abstract

A pattern inspection method including: sequentially imaging plural chip formed on a substrate; selecting at least one of pattern sections of each inspection image obtained by the imaging, while discarding other pattern sections, based on a recipe created in advance, the recipe including information for determining which pattern sections to be selected or discarded; calculating position gap between an inspection image of a chip obtained by the imaging and a reference image stored in a memory by using positional information of pattern images included in the inspection image and reference pattern images which are both corresponding to the at least one of pattern sections selected at the selecting; aligning the inspection image and the reference image by using information of the calculated position gap; and comparing the aligned inspection image with the reference image, and extracting a difference between the two images as a defect candidate.

Claims

1. A pattern inspection method comprising:

sequentially imaging plural chips formed on a substrate;

selecting at least one of pattern sections of each inspection image obtained by the imaging, while discarding other pattern sections, based on a recipe which is created in advance, the recipe including information for determining which pattern sections are to be selected and other pattern sections to be discarded, wherein the at least one of pattern sections are parts of an object to be inspected for which amounts of displacement of the object to be inspected are used for determining alignment of the object to be inspected, and the recipe is created in advance by using another substrate different from the substrate to be inspected, the another substrate being same kind or type as the substrate;

calculating a position gap between an inspection image of a chip obtained by the imaging and a reference image stored in a memory, by using positional information of pattern images included in the inspection image and reference pattern images included in the reference image, which are both corresponding to the at least one of pattern sections selected at the selecting step based on the recipe created in advance using said another substrate;

aligning the inspection image and the reference image by using information of the calculated position gap based on the positional information of pattern images of the inspection image and the reference pattern images corresponding to the at least one of pattern sections selected in the selecting step based on the recipe created in advance using said another substrate which recipe includes information for determining which pattern sections are to be selected to determine alignment and which pattern sections are to be discarded, and not used for alignment; and

comparing the aligned inspection image with the reference image, and extracting a difference between the two images as a defect candidate.

2. A pattern inspection method according to claim 1,

wherein the another substrate is run through a same process as the substrate.

3. A pattern inspection method according to claim 1,

wherein in the calculating, calculating position gap based on the recipe which further includes a calculating process.

4. A pattern inspection method according to claim 3, wherein in the calculating, calculating position gap in accordance with an order of calculating to be determined in the recipe.

5. A pattern inspection apparatus comprising:

an image acquisition unit which sequentially detects image of a manufactured product on which plural chips are formed;

a pattern selecting unit for selecting at least one of pattern sections of each inspection image obtained by the image acquisition unit, while discarding other pattern sections, based on a recipe which is stored in advance, the recipe including information for determining which pattern sections to be selected and other pattern sections to be discarded, wherein the at least one of pattern sections are parts of an object to be inspected for which amounts of displacement of the object to be inspected are used for determining alignment of the object to be inspected, and the recipe is created in advance by using another manufactured product different from the manufactured product to be inspected, the another manufactured product being same kind or type as the manufactured product;

a calculating unit for calculating position gap between an inspection image of a chip formed on the substrate and a reference image stored in a memory, by using positional information of pattern images included in the inspection image and reference pattern images included in the reference image which are both corresponding to the at least one of pattern sections selected by the pattern selecting unit based on the recipe created in advance using said another manufactured product;

an aligning unit for aligning the inspection image with the reference image by using a calculated position gap based on the positional information of pattern images of the inspection image and the reference pattern images corresponding to the at least one of pattern sections selected in the selecting step based on the recipe created in advance using said another substrate which recipe includes information for determining which pattern sections are to be selected to determine alignment and which pattern sections are to be discarded, and not used for alignment;

an defect candidate extracting unit which compares the aligned inspection image with the reference image, and extracting a difference between the inspection image and the reference as a defect candidate.

6. A pattern inspection apparatus according to claim 5, wherein the image acquisition unit comprises:

a light source for irradiating light on the manufactured product;

an image sensor for detecting image front light reflected from the manufactured product and dividing the image into a plurality of pattern sections.

7. A pattern inspection apparatus according to claim 5,

wherein the recipe is created by using information of the another manufactured production which had been inspected, the another manufactured product running through same process as the manufactured product.