CN114814503A

CN114814503A - Real-time analysis of test results of semiconductor tester

Info

Publication number: CN114814503A
Application number: CN202110034635.3A
Authority: CN
Inventors: 杨磊
Original assignee: Suzhou Qijian Software Co ltd
Current assignee: Suzhou Qijian Software Co ltd
Priority date: 2021-01-19
Filing date: 2021-01-19
Publication date: 2022-07-29

Abstract

The invention provides a method for analyzing test data of a semiconductor tester in real time, which comprises the following steps: the method comprises a real-time data reading step and a real-time analysis step, wherein the real-time data reading step reads a test file at a fixed frequency. And in the real-time analysis step, the read data is disassembled and combined according to rules to obtain single complete data for analysis. The method for analyzing the test data of the semiconductor tester in real time analyzes the test file in real time to help find the abnormity in the test process in time and rapidly and reduce the production loss to the minimum.

Description

Real-time analysis of test results of semiconductor tester

Technical Field

The invention relates to a method for analyzing test data of a semiconductor tester in real time, and belongs to the field of semiconductor testing.

Background

In the semiconductor testing industry, the testing results of testing machines are mostly stored in the format of STDF (standard test data format). The format stores test data in binary system, and has the characteristic of being unreadable by human. In the existing system, after the wafer test is finished, the test file is imported into special analysis software for analysis, the analysis means is too late, the analysis result only can play a reference correction role for the subsequent wafer test, and whether the calibration is accurate or not cannot be verified in time because the subsequent wafer test process cannot be analyzed in real time.

Disclosure of Invention

The invention aims to provide a method for analyzing test data of a tester in real time, which can find abnormality in the test process in time and quickly and reduce production loss to the minimum.

The invention adopts the following technical scheme:

a method for analyzing test data of a testing machine in real time, comprising:

a real-time data reading step and a real-time analysis step,

the real-time data acquisition steps are as follows:

the method comprises the following steps: monitoring whether a new test file is generated or not,

step two: checking whether the size of the file is increased according to the fixed frequency, if so, entering a third step, otherwise, entering a fourth step,

step three: if the currently read test file grows, the growing data continues to be read,

step four: the new file is set as a read object,

step five: and repeating the steps one to four.

The real-time analysis steps are as follows:

step six: firstly, a buffer is established, named as ByteBuffer, which is 0 byte initially,

step seven: the newly added data of the file is read,

step eight: the newly read data is merged with the data in the buffer ByteBuffer,

step nine: judging whether the size of L (ByteBuffer) + L (data) is more than or equal to 4bytes, if yes, entering step eleven, if no, entering step ten,

step ten: if the result is less than the result indicating that the Header data received this time is incomplete and not long enough, the data is stored in the buffer ByteBuffer,

step eleven: the first 4bytes of the read data are taken, then step twelve,

step twelve: an STDF Header is initialized and,

step thirteen: judging whether the Header data is valid, if yes, entering a seventeenth step, if not, entering a fourteenth step,

fourteen steps: judging Record length required by the STDF Header Record and length of L (data) -L (Header), if the Record length is less than the Record length, entering a step fifteen, otherwise entering a step sixteen,

step fifteen: the result is that the Record data needed at this time is less than the incomplete data and the length is insufficient, the data is stored into the buffer ByteBuffer,

sixthly, the steps are as follows: if the result is equal to or greater than L (record), reading the data with length L (record), proceeding to step seventeen,

seventeen steps: a complete STDF record is parsed out,

wherein L (record) is the length of a complete record in the data packet with the Header part removed,

l (bytebuffer) is the last in-cache length,

l (data) is the data length read this time,

l (Header) is the length of the Header,

eighteen steps: the cache ByteBuffer is cleared and,

nineteen steps: repeating the steps seven to eighteen.

Advantageous effects of the invention

The method for analyzing the test data of the machine in real time has the following advantages:

1. and the real-time performance is realized, the statistical analysis of the whole wafer can be displayed in real time when the machine writes data once, and the statistical analysis of the whole production batch can be displayed in real time, so that a user can customize a card control rule and make a quick alarm and stop response.

2. The whole analysis process of the method does not need human participation. And reading, analyzing and alarming from the test file in real time.

3. The method provides a method for quickly disassembling and combining the data. The temporary file generated by the testing machine can also analyze the information.

4. And problem testing is reduced. The abnormality can be accurately analyzed through partial tested chips, the test can be stopped in time, and the abnormality is suddenly increased compared with 3/4 chips with continuous failures; the failed chips show regularity in the wafer, and the anomalies can be detected even if a problem is found in the real-time test process. Before the test is started, the program of the test can be judged according to the information provided in the test file, and whether the parameters are accurately set or not can be judged.

Drawings

FIG. 1 is a flow chart of data reading;

FIG. 2 is a flow chart of analyzing a test file in real time.

Detailed Description

The following describes embodiments of the present invention with reference to the drawings.

As shown in fig. 1, the whole system is composed of two parts, namely, acquisition and analysis, real-time reading of test files generated by a machine, real-time test data merging and analysis, and real-time analysis and statistics:

because the test items are different from test product to test product, the time required by the tester to test one chip is different, and the writing time interval is different. Therefore, a fixed time interval acquisition mode is adopted during STDF data disassembly, and the acquisition frequency is set to be read every 5 seconds.

As shown in fig. 2, the real-time test data reading process is as follows:

step S1: monitoring whether a new test file is generated, if so, entering the step S2: if not, the process proceeds to step S3.

Step S2: marking new test files as collection objects

Step S3: checking the size of the test file according to a fixed time interval, judging whether the file is increased, if so, entering a step S4, and if not, continuing monitoring;

step S4: reading the growing part of the file;

step S5: recording the last read end position of the current file

And repeating the steps.

Merging and analyzing the real-time STDF data:

the STDF protocol specifies that each valid Record consists of two parts, Header (4bytes) + Record. The single-write STDF Message of the tester may be only part of the content of one record, or may be composed of a plurality of records. Each received STDF Message must be merged again to resolve valid information.

Step S6: firstly, establishing a byte stream buffer named as ByteBuffer, wherein the length is not fixed, the initial length is 0 byte, and the byte stream buffer is used for storing data under the condition that Header information is insufficient or Record information is insufficient

Step S7: reading the data of the test file, marking the end position of the reading in the file

Step S8: judging whether there is data in the buffer memory, if so, merging the read data and the newly read data

Step S9: and judging whether the merged data has a Header with the length of 4bytes or not, if so, entering the step S11, and if not, entering the step S10.

Step S10: a Header with the length of 4-L (Header) is intercepted from the data packet MSG and added into a buffer ByteBuffer, wherein the L (Header) represents the incomplete Header part split from the data last time.

Step S11: the first 4bytes are parsed and step 12 is entered to initialize an STDF Header.

Step S12: an STDF Header is initialized and,

step S13: judging whether the Header data is valid, if yes, entering step S13, if no, entering step S12,

the length and format of the Header are fixed, and Type and SubType are defined in the protocol with special meaning for each value, and not any data is valid. If the analyzed data is no longer within the protocol definition range. This Record is not processed and is discarded directly.

Step S14: and discarding invalid data and clearing the cache.

Step S15: the remainder of the STDF record was obtained: l (record), then proceeds to step S14,

step S16: comparing the length indicated by L (record) and Header, if less than, proceeding to step S15, otherwise, proceeding to step S16

l (bytebuffer) is the last in-cache length,

l (data) is the data length read this time,

l (Header) is the length of the Header,

step S15: if the result is larger than the data which indicates that the data received this time is incomplete and the length is not enough, the data with the length of L (data) -L (header) is stored in the ByteBuffer,

step S17: the data is sufficient, a complete STDF record is parsed,

step S18: clearing cache ByteBuffer

Steps S4 to S17 are repeated.

Claims

1. A method of analyzing test data of a semiconductor testing machine in real time, comprising: a real-time data reading step and a real-time analyzing step.

The real-time data reading steps are as follows:

step two: checking whether the size of the file is increased or not according to fixed interval time, if so, entering a third step, and otherwise, entering a fourth step;

step three: if the test file grows, the growing data continues to be read,

step four: the new file is set as the acquisition object,

step five: and repeating the steps one to four.

The real-time analysis steps are as follows:

step seven: the newly added data of the file is read,

step ten: if the result is less than the result indicating that the Header data received this time is incomplete and insufficient in length, the data is stored into the buffer ByteBuffer,

step eleven: taking the first 4bytes of the read data, and entering the step twelve

Step twelve: an STDF Header is initialized and,

fourteen steps: judging Record length required by STDF Header Record and length of L (data) -L (Header), if it is less than said length, making step fifteen, otherwise making step sixteen,

step fifteen: the result is that the Record data which is less than the needed data is incomplete and has insufficient length, the data is stored into the buffer ByteBuffer,

seventeen steps: a complete STDF record is parsed out,

eighteen steps: the cache ByteBuffer is cleared and,

nineteen steps: repeating the steps seven to eighteen.

2. The method of analyzing test data of a semiconductor testing machine in real time as set forth in claim 1, wherein: in the second step, the time interval for monitoring the file change is 5 seconds.

3. The method of analyzing test data of a semiconductor testing machine in real time as set forth in claim 1, wherein: the data read in a single time is any byte not less than 0.

4. The method of analyzing test data of a semiconductor testing machine in real time as set forth in claim 1, wherein: in step ten, when the data is incomplete, the incomplete data is stored in the buffer area.