JPH0992701A - LSI failure analysis support device using database - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a failure analysis support system in which past case of analysis can be referred quickly upon occurrence of a similar failure by storing and managing a failure analysis procedure data of an LSI and an analytical result data which is decided as a criterion of the failure by a work device at each stage. SOLUTION: A work procedure storing/managing means 201 stores a data representative of work procedure hierarchically and an analytical result storing/ managing means 202 stores a failure analysis data, respectively, on magnetic discs. Based on retrieving conditions, e.g. data items, received from an input means connected with a personal computer and a work station, a retrieving means 203 retrieves analytical results satisfying the retrieval conditions among analytical results being managed by the analytical result storing/managing means 202 and transfers the retrieved results to a display/input means 204. According to the system, the past case of analysis can be referred quickly upon occurrence of similar failures and an analytical procedure can be designated by a person other than the expert of failure analysis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LSI failure analysis support apparatus using a database, and more particularly to a database for supporting an operator who identifies a failure location of a failed LSI chip and investigates the cause of the failure. It is about.

[0002]

2. Description of the Related Art LSI failure analysis is to prevent malfunctions in an initial test or to find a failure point of an LSI chip that has failed during use, and to investigate the cause of the failure so that the same failure will not occur again. This is a technology for examining corrective actions to be taken.

In the conventional LSI failure analysis, the time and cost required for the failure analysis are increasing with the sophistication of the LSI manufacturing process technology. Therefore, improvement of the failure analysis technology is required as a countermeasure. There is.

As a measure for improving the failure analysis technique, first, an operator who performs failure analysis attaches an electron microscope or an EB tester (Electron) to a personal computer connected by a network.
Beam tester: An electron beam tester) or other LSI failure analysis device outputs an output image of a failure location through a video capture board, and further, the captured image is connected to a personal computer or an external storage device such as a removable hard disk or an optical disk. It is stored in the device.

Other workers should refer to the output image of the faulty part stored in the above-mentioned external storage device, that is, all the workers should share the result of the fault analysis performed by the other workers. To improve the failure analysis technology of workers,
A technique that improves the efficiency of analysis work is described in “Steve
Morris, Ed Black, "THE ADVENT OF THE PAPERLESS FAIL
URE ANALYSIS INFORMATION SYSTEM, "ISTFA 1990 Inter
national Symposium for Testing and Failure Analysi
s pp. 81-87. ”.

[0006] Another technique is described in reference (2), "Laurel".
M. Bellay, PBGhate, Lawrence C. Wagner, "COMPUTERS I
N FAILURE ANALYSIS, "ISTFA 1990 International Symp
osiumfor Testing and Failure Analysis pp.89-95.
Have been introduced to.

According to the technique of this reference (2), the failure analysis data input from the personal computer is stored in the relational database on the large-scale computer.

It has a Pareto analysis function and a failure guide function by an expert system, and collects failure analysis data and stores it in a large computer for use in analysis support. By providing the above-mentioned function, not only the failure analysis data can be used more easily, but also the current failure analysis can be made efficient through the expert system.

As another technique, an expert system for supporting failure analysis of a CMOS integrated circuit is available.
Reference (3), "Christopher L. Henderson and Jerry M.
Soden, "ICFAX, An Integrated Circuit Failure Analy
sis Expert System, "1991 IEEE / IRPS pp.142-151."

The above-mentioned expert system not only makes it easier to analyze failure analysis data, but also makes failure analysis more efficient through the expert system.

As another technique, an expert system for automatically performing a failure analysis of a memory LSI is disclosed in "T. Tsujide, et.al.," Automatic Memory fail.
ure Analysis Using an Expert System in Conjunction
with a memory Tester / Analyzer, "IEEE / IRPS 1993, P
P.184-189. ”

In this expert system, the memory L
A correspondence table showing the relationship between the SI failure mode and the functional operation test is created and the failure point is estimated by the expert system.

[0013]

SUMMARY OF THE INVENTION As a result of studying the above prior art, the present inventor has found the following problems.

In the conventional LSI failure analysis support device, an LSI using the database described in the document (1) is used.
Since the failure analysis support device in (1) focused on sharing the analysis results accumulated by each worker who carried out failure analysis with all the workers, the procedure leading to the results was considered. There wasn't.

For this reason, as for the materials used for the failure analysis and the description of the procedure leading to the result, there are many cases where the information amount is insufficient, and the experience of other operators who have analyzed similar failures should be fully utilized. There was a problem that I could not do it.

Further, in the failure analysis support apparatus for LSI using the expert system described in the documents (2) and (3), failure modes and analysis methods are different for each kind of product, such as a logical LSI, and all kinds of products are used. Can not generalize and rule the parsing procedure corresponding to
Since the analysis procedure at the time of performing I failure analysis cannot be completely established as knowledge, as in the example shown in the document "ICFAX" of (3), the problem that only LSI failures can be adapted to very simple failures was there.

Further, since the failure analysis of the LSI so far has been carried out by each worker based on his or her own experience, there is a problem that it takes time to pass the skill to an unskilled person.

An object of the present invention is to provide a technique capable of quickly referring to past analysis cases when a similar failure occurs.

Another object of the present invention is to provide a technique capable of instructing an analysis procedure so that a person who is not a failure analysis expert can perform analysis.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0021]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

(1) An external storage device for storing data,
A first information processing device having a database management unit for managing data stored in the external storage device; and at least one second information processing device connected to the first information processing device via a communication network. In a failure analysis support apparatus for an LSI using a database, the external storage device includes work procedure data for failure analysis of the LSI, judgment reference data for determining whether or not there is a failure at each stage of the work procedure, and the work procedure. The database control unit includes a database file having analysis result data determined by an operator from the observation results obtained based on the above, and the database control unit includes work procedure data for LSI failure analysis and failure at each stage of the work procedure. Work procedure storage management means for managing the storage of judgment criterion data for judging presence and absence, and work based on the observation results obtained based on the work procedure Analysis result storage management means for managing the storage of the analysis result data determined by, and related information management means for managing the analysis result data and all work procedures executed to obtain the analysis result data and the association. .

(2) The related information management means of (1) has a one-to-one correspondence between the symbols of the flowchart expressing the work content of the failure analysis of the LSI and the work procedure data.
And the work procedure is searched by selecting the symbol.

According to the above-mentioned means (1), the related information management means stores in the external storage device the LS performed in the past.
Since the analysis result data of the failure analysis of I and the series of work procedures executed to obtain the analysis result are managed in association with each other, for example, when the worker performs the failure analysis of the LSI, the worker fails. By searching for past analysis results using symptoms associated with
It is possible to obtain an analysis result when a failure analysis of an LSI having a symptom similar to that of the I failure is obtained, and it is possible to refer to the work procedure and the judgment standard performed to obtain the analysis result.

Therefore, since the worker can perform the failure analysis work based on the past work procedure obtained by the search, it is possible to perform the failure analysis of the LSI without performing unnecessary work.

According to the above-mentioned means (2), the standard work procedure for LSI failure analysis is set as a symbol in the flowchart, and the work procedure data managed by the symbol and the procedure storing means and each procedure are stored. By associating the judgment reference data with the related information management means, the worker can perform the failure analysis of the LSI by advancing the work and judgment displayed as symbols in the flowchart according to the flowchart. Even an unskilled person can easily perform the failure analysis of the LSI.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings together with embodiments (examples) of the invention.

In all the drawings for describing the embodiments of the present invention, components having the same functions are denoted by the same reference numerals, and their repeated description will be omitted.

FIG. 1 is a block diagram showing a schematic configuration of an LSI failure analysis support apparatus using a database according to an embodiment of the present invention. 1 is a data processing room, 2 is an analysis work room, and 3 is a communication network. 4 is a personal computer a (personal computer a second information processing device), 5 is a personal computer b (personal computer b, second information processing device), 6 is an image scanner a, 7 is a printer, 8 is a workstation a ( Reference numeral 9 denotes a workstation b (second information processing apparatus), 10 denotes a magnetic disk device (external storage device), and 11 denotes an image scanner b.

In FIG. 1, the data processing room 1 is equipped with a personal computer a4, a personal computer b5, an image scanner a6 and a printer 7, and the personal computer a4 or personal computer b is used.
5, the result of failure analysis can be input and the progress can be referred to.

The analysis work room 2 has a workstation a.
8, a workstation b9, a magnetic disk 10, and an image scanner b11, and a light emission / heat generation analysis device (not shown), OBIC (Optical Beam I).
nduced Current) and EB tester (E
electron beam tester: electron beam tester)
It is possible to input the analysis result of the LSI performed by using and display the data such as the work procedure.

The communication network 3 includes personal computers a, b (4, 4) installed in the data processing room 1 and the analysis work room 2.
5), the workstations a, b (8, 9) and the printer 7 are connected.

The personal computers a and b (4,5) are well-known information processing devices and can confirm the result of failure analysis and the progress of the process. In particular, the personal computer a4 is connected to a well-known image scanner 6, Using this image scanner 6, a drawing, a photograph, etc. can be input as image data to an LSI failure analysis support device using the database of the present embodiment.

The printer 7 is a well-known printer, and is a personal computer a, b (4,5) connected to the communication network 3.
Data can be printed from the workstations a and b (8, 9) and a hard copy of the display screen can be taken.

The workstations a, b (8, 9) are
This is a well-known information processing device, and an LSI performed by using a light emission / heat generation analysis device, an OBIC, and an EB tester (not shown).
The analysis result can be input and data such as work procedure can be displayed, and in particular, the workstation b9 has a function as a database server.

The magnetic disk device 10 is connected to the workstation b9 and stores work data of a failure analysis work procedure and data of a result of the failure analysis as a database file.

FIG. 2 is a functional block diagram showing a schematic configuration of the database control unit of the workstation b9. 200 is a database control unit, 201 is a work procedure storage management unit, 202 is an analysis result storage management unit, and 203 is a search. Means, 204 is a display / input means, and 205 is a related information management means.

In FIG. 2, work procedure storage management means 20
1 manages work procedure data in which work procedures are hierarchically described, as will be described later. The work procedure data includes (a) for expressing faulty parts such as IC type, lot name, and wafer number. (B) Data such as conditions, results, judgment criteria, etc. for expressing work procedure contents (c) Representative photographs and drawings for visually expressing work contents.

Further, these work procedure data are stored in the magnetic disk device 10 as a database file.

The data managed by the analysis result storage management means 202 is the data showing the outline of the failure analysis, and (A) the data item (B) for expressing the failed part such as IC type, lot name and wafer number. ) Observation results by a failure analysis device such as a light emission / heat generation analysis device, an OBIC and an EB tester, and conditions under which they are observed (C) Failure mechanism obtained from the analysis result (D) Photos and drawings showing the failure mechanism described above Manage the analysis result data such as.

Further, these analysis result data are stored in the magnetic disk device 10 as a database file.

The search means 203 uses the personal computers a, b (4,
5) and the data items etc. input from the input means (not shown) connected to the workstations a, b (8, 9) are used as the search conditions, and the search results are selected from the analysis results managed by the analysis result storage management means 202. The matching analysis result is retrieved and transferred to the display / input means 204.

As a method of displaying the search results, in addition to the method of displaying the analysis results matching the search conditions one by one,
Since it is possible to display a photograph and a drawing showing the failure mechanism shown in (D) above as a list, the operator can grasp the failure tendency by the image.

The display / input means 24 is a part for controlling input / output to / from the database, and is a workstation b9.
An instruction to the database input from the input means (not shown) is input to the work procedure storage management means 201, the analysis result storage management means 202 and the search means 203, and at the same time, the work procedure storage management means 201, the analysis result storage management means 202 and the search. The output of the means 203 is output to the output means connected to the workstation b9 and displayed.

The related information management means 205 uses a well-known technique and is obtained by a plurality of work procedure data stored as a database file in the magnetic disk device 10 and a series of work procedures indicated by the work procedure data. 1
Create a link file to manage the information associated with the analysis results.

Therefore, the worker is the magnetic disk device 1
While referring to the analysis result stored in 0, the work procedure related to the analysis result can be read out from the magnetic disk device 10 to be referred to, and while referring to the work procedure, the analysis result related to this work procedure can be read out. You can also refer to it.

When the management of the analysis condition or the analysis result is changed from the work procedure storage management means 201 to the analysis result storage management means 202, it is applicable based on the related information (link file) managed by the related information management means 205. The management of analysis conditions or analysis results can be changed from work procedure data to analysis result data corresponding to this work procedure data.

FIG. 3 is a flow chart showing the first layer of the flow chart showing the standard work procedure of LSI failure analysis managed by the work procedure storage management means 201. In step 301, the location of the failure is specified, and then, Step 302
In step 303, the structure of the failure point is specified, and in step 303, the cause of the failure is identified.

FIG. 4 is a flow chart showing the work procedure of the second layer when the step for identifying the location of step 301 shown in FIG. 3 is expanded.
01 indicates that an LSI test (LSI operation test) is to be performed, and then a failure type is selected from failure type A402 to failure type C404 based on the failure content of the LSI.

FIG. 5 is a flow chart showing the work procedure for the failure type C in step 404 shown in FIG. 4, and the work data shown below is stored.

First, it is confirmed whether the LSI which is the object of the failure analysis is packaged (step 501) or remains on the wafer (step 502), and light emission analysis is performed in step 503.

Next, in step 504, heat generation analysis is performed,
In step 505, the operator specifies the position of the light emission / heat generation point on the LSI layout and estimates the cause of the failure from the result (step 506).

At step 507, the worker performs step 5
It is determined from the result estimated in 06 whether the inspection by the EB tester is necessary, and if necessary, the EB tester is prepared in step 508, and the failure point is specified by the EB tester (step 5
09), and structural analysis is performed in step 510.

FIG. 6 is a view showing an example of a screen display of work procedure data. For example, the LSI type, the wafer lot number, the input data, the condition, the result, the output data, the judgment,
Data part consisting of next procedure, registrant, registration date, analysis item, representative photograph and comment and procedure type, and representative photograph / figure, switching to failure analysis data screen, saving, deleting and linking instructions. It consists of a command section.

FIG. 7 is a diagram showing an example of a screen display of analysis result data. The type of LSI, the lot number of the wafer, the location, the light microscope coordinates, the design coordinates, the block, the cell library,
Cell name, registrant, registration date, representative photograph and comment, cause of failure mechanism, structure, remarks, failure occurrence, tester,
Whether to emit light, whether to generate heat, observation result (EB) by EB tester, data part consisting of plane and cross section, search, switching to procedure input screen, representative photograph / drawing display,
It consists of command parts for registering, saving and deleting new data.

Next, FIG. 8 shows a flowchart for explaining the operation of the LSI failure analysis support apparatus using the database of the present embodiment, and the database of the embodiment of the present invention will be described below based on this flowchart. Used L
The operation of the SI failure analysis support device will be described.

The activation of the LSI failure analysis support apparatus using the database is the start of this flowchart, and first,
The worker displays the screen of the work procedure data shown in FIG.
Enter your name (step 801), then display and enter the analysis result data screen to enter sample names such as LSI product name, lot name, wafer number and chip number to be analyzed. Is performed (step 802).

Next, when the worker retrieves the display symbol of the first step work flow chart shown in FIG. 3 to display the flow chart (step 803) and selects the symbol indicating the work to be performed (step 804), The work procedure management unit 201 provides information such as drawings, data (including photographs) to be prepared in advance when performing the selected work, information about which analysis device and how to obtain the necessary data on the magnetic disk. It is read from the device 10 and displayed (step 805).

Since the operator can obtain the instructed data (photograph and data of the analysis result) by operating the analysis device based on the displayed information, the failure of the LSI using the database of the present embodiment. PC a, b (4,5) of analysis support device or workstation a,
By inputting the data obtained by the operator from b (8, 9) into the database of the workstation b (9) and performing a search, the search means 203 reads the data that matches the condition from the magnetic disk device 10. By
Data of the analysis result corresponding to the work shown in step 805 is displayed (step 806).

Next, the worker causes the search means 203 to execute a search by using the items related to the work currently being performed as keywords, and the search means 203 executes the search based on the link file managed by the related information management means 205. Among the analysis result data stored in the magnetic disk device 10, related similar data analyzed in the past (photographs, symptoms, etc.)
Is displayed as shown in FIG. 7, and the operator narrows down the cause of the current phenomenon by comparing the observation result obtained from the analysis device with the past result obtained by the search (step 807).

At this time, it is possible to display the above-mentioned drawings by previously inputting the LSI layout diagram, sectional view, circuit diagram, and the like to be analyzed in the LSI failure analysis support device using the database. .

Next, the operator estimates the failure mechanism,
Enter the criteria that led to the estimation result (step 80
8) In the next step 809, it is determined whether further analysis is to be performed or to end the analysis. If it is determined that the analysis is to be ended, the analysis work is ended here.

On the other hand, when it is determined that another work is to be performed, the process returns to step 803 and another analysis test is performed until the worker can determine that the work is finished.

As described above, according to the LSI failure analysis support apparatus using the database of this embodiment,
The related information management unit 205 manages in the link file the analysis result of the failure analysis of the LSI performed in the past stored in the magnetic disk device 10 and the series of work procedures executed to obtain the analysis result in association with each other. Therefore, for example, when a worker performs a failure analysis of an LSI, the worker retrieves past analysis results by using a symptom associated with the failure as a search keyword to obtain an analysis result similar to the aforementioned LSI failure. It is possible to refer to the work procedure and the judgment standard performed for obtaining the analysis result.

Therefore, since the worker can perform the failure analysis work based on the past work procedure obtained by the search, the failure analysis of the LSI can be performed without performing unnecessary work.

Further, the standard work procedure for failure analysis of the LSI is set as a symbol in the flow chart, and the symbol, the work procedure stored in the magnetic disk device 10 and the judgment standard for each procedure are related information managing means 205. By associating with each other, the worker advances the work and the judgment displayed as symbols in the flow chart according to the flow chart.
Since the failure analysis can be performed, even an unskilled person can easily perform the failure analysis of the LSI.

Further, since it is possible to refer to past judgment criteria and the like, even an unskilled person can make an accurate judgment.

Further, since the workstation b9 having a database, the personal computers a, b (4,5) and the workstation a8 are all connected by the communication network 3, it is separated from the analysis work room 2 which is the site of the analysis work. Workstation b9 with database
By accessing, it is possible to confirm the progress of the failure analysis of the LSI in real time.

In this embodiment, the workstation b9 is used as the first information processing apparatus, and the personal computers a, b (4,5) and the workstation a8 are used as the second information processing apparatus. Needless to say, the information processing apparatus is not limited to the above-described information processing apparatus, and other information processing apparatus may be used.

Further, in the present embodiment, the operation and action have been described using the magnetic disk device 10 as the external storage device, but the present invention is not limited to the magnetic disk device 10 and other magneto-optical disk devices. It goes without saying that a device using a storage medium capable of random access such as the above and rewritable storage contents can be used.

As described above, the invention made by the present inventor is:
Although specifically described based on the embodiments of the present invention, the present invention is not limited to the embodiments of the present invention, and it is needless to say that various modifications can be made without departing from the gist of the present invention. .

[0072]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

(1) When a similar failure occurs, past analysis cases can be referred to quickly.

(2) The analysis procedure can be instructed so that even a person who is not a failure analysis expert can perform analysis.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an LSI failure analysis support apparatus using a database according to an embodiment of the present invention.

FIG. 2 is a functional block diagram showing a schematic configuration of a database control unit included in a workstation b.

FIG. 3 is a flow chart showing a first layer of a flow chart showing a standard work procedure of LSI failure analysis stored in a work procedure storage management means.

FIG. 4 is a flowchart showing a work procedure of a second layer when the step for specifying the location of step 301 shown in FIG. 3 is expanded.

5 is a flowchart showing a work procedure for failure type C in step 404 shown in FIG.

FIG. 6 is a diagram showing an example of a screen display of work procedure data.

FIG. 7 is a diagram showing an example of a screen display of analysis result data.

FIG. 8 is a flowchart for explaining the operation of the LSI failure analysis support apparatus using the database according to the present embodiment.

[Explanation of symbols]

1 ... Data processing room, 2 ... Analysis work room, 3 ... Communication network, 4 ... Personal computer a, 5 ... Personal computer b, 6 ... Image scanner a, 7 ... Printer, 8 ... Workstation a, 9 ... Workstation b 10 ... Magnetic disk device, 11 ... Image scanner b, 200 ... Database control unit, 201 ... Work procedure storage management means, 202 ... Analysis result storage management means, 203
... Search means, 204 ... Display / input means, 205 ... Related information management means.

Claims (2)

[Claims] 1. A first information processing device having an external storage device for storing data, a database management unit for managing data stored in the external storage device, and a communication network for the first information processing device. In a failure analysis support apparatus for an LSI using a database including at least one second information processing apparatus connected, the external storage device includes work procedure data for failure analysis of the LSI, at each stage of the work procedure. Of a failure analysis of LSI, the database control unit includes a database file having determination result data for determining the presence or absence of a failure and analysis result data determined by an operator from an observation result obtained based on the work procedure. Work procedure storage management means for managing storage of work procedure data and judgment reference data for determining whether or not there is a failure at each stage of the work procedure; The analysis result storage management means for managing the storage of the analysis result data determined by the operator from the observation result obtained based on the work procedure, and the analysis result data and all the work executed to obtain the analysis result data. An LSI failure analysis support device using a database, comprising: a procedure and related information management means for managing association. 2. The related information management means associates a symbol of a flow chart representing the work content of the failure analysis of the LSI with the work procedure in a one-to-one correspondence, and selects the symbol to perform the work procedure. L using the database according to claim 1, characterized in that
SI failure analysis support device.