Apparatus for analyzing a failure of a semiconductor device and method thereof
First Claim
1. An apparatus for analyzing a failure of a semiconductor device, which calculates a failure die number/rate, a failure bit map (FBM) yield and a die/sorting (D/S) yield on a test mode of each test wafer, the apparatus comprising:
- a wafer map memory for storing test result data of said each test wafer;
a means for calculating a failure die number/rate, a D/S good die number/yield and a FBM good die number/yield on the test mode of said each test wafer;
a means for storing the calculated values;
a means for calculating, in case a failure bit mode to be defined is selected from a plurality of failure bit modes, a failure die rate for total dies and a failure die rate for total failure dies based on a total die number and a failure die number of the selected failure bit mode;
a means for calculating an expected FBM yield based on the FBM yield and the failure die rate for the total dies and calculating an expected D/S yield based on the expected FBM yield, the FBM yield and the D/S yield;
a means for calculating an average D/S yield of the selected failure bit mode based on the expected FBM yield, the FBM yield and the D/S yield of the selected test wafer;
a means for calculating a maximum/minimum yield based on the expected FBM yield, and a minimum and a maximum deviation value between the FBM yield and the D/S yield; and
a means for displaying the calculated values on a monitor.
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Abstract
In an apparatus for analyzing a failure of a semiconductor device, a wafer map memory stores test result data of each test wafer. A failure die number/rate, a D/S good die number/yield and a FBM good die number/yield on each test mode of each test wafer are calculated. In case a failure bit mode to be defined is selected from a plurality of failure bit modes, a failure die rate for total dies and a failure die rate for total failure dies are calculated. An expected FBM yield, an expected D/S yield, an average D/S yield, and a maximum/minimum yield are calculated. The calculated values are displayed on a monitor.
8 Citations
4 Claims
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1. An apparatus for analyzing a failure of a semiconductor device, which calculates a failure die number/rate, a failure bit map (FBM) yield and a die/sorting (D/S) yield on a test mode of each test wafer, the apparatus comprising:
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a wafer map memory for storing test result data of said each test wafer;
a means for calculating a failure die number/rate, a D/S good die number/yield and a FBM good die number/yield on the test mode of said each test wafer;
a means for storing the calculated values;
a means for calculating, in case a failure bit mode to be defined is selected from a plurality of failure bit modes, a failure die rate for total dies and a failure die rate for total failure dies based on a total die number and a failure die number of the selected failure bit mode;
a means for calculating an expected FBM yield based on the FBM yield and the failure die rate for the total dies and calculating an expected D/S yield based on the expected FBM yield, the FBM yield and the D/S yield;
a means for calculating an average D/S yield of the selected failure bit mode based on the expected FBM yield, the FBM yield and the D/S yield of the selected test wafer;
a means for calculating a maximum/minimum yield based on the expected FBM yield, and a minimum and a maximum deviation value between the FBM yield and the D/S yield; and
a means for displaying the calculated values on a monitor. - View Dependent Claims (2, 4)
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3. A method for analyzing a failure of a semiconductor device, which calculates a failure die number/rate, a failure bit map (FBM) yield and a die/sorting (D/S) yield on a test mode of each test wafer, the method comprising the steps of:
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(a) calculating a failure die number/rate, a D/S good die number/yield and a FBM good die number/yield on the test mode of said each test wafer;
(b) waiting for a user to select a failure bit mode to be defined from a plurality of failure bit modes;
(c) selecting a certain failure bit mode as a failure bit mode to be defined, and calculating a failure die rate for total dies and a failure die rate for total failure dies based on a total die number and a failure die number of the selected failure bit mode;
(d) calculating an expected FBM yield based on the FBM yield and the failure die rate for the total dies;
(e) calculating an expected D/S yield based on the expected FBM yield, the FBM yield and the D/S yield;
(f) calculating an average D/S yield of the selected failure bit mode based on the expected FBM yield, the FBM yield, and the D/S yield of the selected test wafer;
(g) calculating a maximum and a minimum yield based on the expected FBM yield, and a maximum and a minimum deviation value between the FBM yield and the D/S yield;
(h) displaying the calculated values on a monitor; and
(i) iteratively performing the steps (c) to (h) whenever a new failure bit mode is selected as a failure bit mode to be defined.
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Specification