JP3140877B2 - Process flow check and simulation equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object to be treated,
The present invention relates to a device that performs a check and simulation of a process flow that describes a series of flows of processes having different process types and processing conditions by a computer, not by a human.

[0002]

2. Description of the Related Art Generally, when an engineer / researcher creates a process flow (a series of processing flows), a completed process flow is not always correct. For example,
In the case of the LSI process flow shown in FIG. 6, there is an error such as no inspection step after the lithography step.

Conventionally, these checks have been performed by experts in the field. But,
In many fields represented by LSIs, the number of skilled workers is insufficient, and the number of processes (processes) for one processing target (product) tends to increase sharply. As a result, a check by a human (expert) is uneconomic in terms of the time required.

[0004] In the future, it will be expected that mistakes in checking will easily occur even for a skilled person due to excessive concentration of the checking work on the skilled person.

In order to solve such a problem, a check by a computer has been proposed or partially put into practical use. However, the expression format of check rules that is easy for humans to understand depends on the purpose, content, and meaning of each process, and the format that is easy for a computer to process is the type and condition of each process (physical / chemical). ), There is still a problem with respect to computer checks in the range and extent of rules that can be performed. For example, in the case of checking the rule that the silicon nitride film on the back surface of the wafer must be peeled off before oxidizing the field with respect to the process flow of the LSI shown in FIG. A field oxidation process must be selected.

As a method of solving the problem related to the check by the computer, it is conceivable to give the purpose, content and meaning of the process to the process flow itself. In this case, the number of codes describing the process flow becomes enormous. A new problem that management becomes impossible.

[0007] On the contrary, the rules are used to describe the purpose, contents,
A semantic-independent form, ie, the type of individual processing,
When expressed in a condition-dependent format, it is easy to manage by computer, but another new problem arises that it is very difficult for a human to manage rules.

[0008] Even in the case of performing a simulation by a computer, there is a similar problem because it is necessary to select necessary information from a process flow in accordance with the purpose, contents and meaning of each processing.

[0009]

As described above, in the case of checking and simulating a process flow, it is expected that a limit will be reached in the near future in the time and accuracy required for the checking and simulation by a human. You.

Further, in the conventional check simulation by computer, the purpose, contents and meaning of each processing cannot be analyzed, so that there is a limit in the range, the degree, and the rule management of rules that can be checked.

An object of the present invention is to solve such a problem and to provide a process flow check device capable of checking and simulating a long and complicated processing flow at a higher speed.

[0012]

In order to achieve the above object, a process flow check / simulation apparatus according to the present invention stores a flow storage unit for storing a process flow consisting of a series of processing conditions, and information on the content of the process. Based on a processing information table stored in association with each processing condition and a processing condition stored in the flow storage unit and a processing condition corresponding to the processing information stored in the processing information table, A processing information generating unit that generates information relating to the contents of the processing conditions stored in the flow storage unit; and state information that simulates a processing state of the process flow based on the information generated by the processing information generating unit. A generation unit, an output information table for storing information about an error accompanying the processing content,
An output information generation unit that outputs an error of a processing condition stored in the flow storage unit based on a comparison between the content of the simulation performed by the processing information generation unit and information stored in the output information table. It is characterized by becoming.

In a preferred aspect of the present invention, a code indicating a type of processing, a variable indicating a condition associated with each processing,
By using a computer to describe the value to be assigned to the variable, and by arranging this combination in the order of the processing flow,
Create a series of processing flow. The created process flow is stored as computer information in a recording medium such as a floppy disk or a hard disk. next,
The saved process flow is prepared in advance on a computer recording medium, for example, a hard disk, after performing the process of adding necessary information if the information required for the check is insufficient before performing the check / simulation. Using some information tables and some information generated during the check simulation,
The check can be performed.

[0014]

As described above, according to the present invention, the check and simulation of the process flow conventionally performed by the expert in the field are performed by the computer. As a result, humans can sufficiently cope with situations that are practically impossible to cope with the ever-increasing number of processes and the complicated flow of processes. Also, the know-how of the check simulation, which has been the knowledge of an expert, can be widely used by many people through a computer and a recording medium.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a functional block diagram of an embodiment of a process flow check / simulation (hereinafter referred to as flow check) apparatus according to the present invention. The flow check device shown in FIG. 1 includes a process flow storage unit 1, a process flow conversion unit 3, an accompanying information table 5, a processing information generation unit 7, a processing information table 9, a state information generation unit 11, a state information table 13, an output information It comprises a generation unit 15, an output information table 17, an environment information table 21, an I / O control unit 23, and an output information output unit 19.

The flow storage unit 1 shows information representing a series of processing flows (hereinafter referred to as flow) in terms of each processing type and condition, for example, a code indicating a semiconductor manufacturing process, and conditions associated with each process. Variables (hereinafter referred to as condition variables),
And a function of loading a flow expressed by a parameter (hereinafter, referred to as a condition variable value) to be assigned to the variable from the storage device 2 (for example, a hard disk) into a main memory of the computer. This information is provided in a format that depends on the type and condition (physical and chemical) of each process that is easy for the computer to process.

The flow conversion unit 3 has a function (hereinafter referred to as flow conversion) for adding missing or simplified information to each processing constituting the flow and converting the information. are doing. Here, the information to be added or converted is, for example, a condition variable and its variable value. The rules for this flow conversion are defined in the accompanying information table 5.

For example, the accompanying information table 5 shown in FIG.
Describes a method of obtaining information to be subjected to flow conversion with respect to a combination of processing information, a condition variable, and a value of the condition variable. At the time of the flow conversion, the I / O control unit 2 interprets the acquisition method and actually acquires the information.
3, the flow conversion unit 3 adds and converts information by exchanging information with the I / O control unit 23. For example,
The process “oxidation, temperature = 1000” in the flow shown in FIG.
.., Gas = steam ”is the condition“ (oxidation) and (temperature = 1000) in the accompanying information table 5 shown in FIG.
C) and (gas = steam). As a result, the accompanying information in FIG. 2 “time = 100 minutes, dielectric strength = excellent”
Is added, and the process of FIG. 3 is performed as shown in FIG.
Temperature = 1000 ° C., gas = steam, time = 1
00 minutes, withstand voltage = excellent ".

As described above, when the process shown in FIG. 3 satisfies the condition of the accompanying information table 5 defined in FIG. 2, the flow converting unit 3 has a function of adding accompanying information corresponding to the condition. ing.

The processing information generating section 7 has a function (hereinafter, referred to as pattern inference) for generating processing information relating to the purpose, contents, meaning, and the like of each processing from a combination pattern of processing (hereinafter, simply referred to as a pattern). ing. here,
The generated processing information includes, for example, the position of the pattern in the flow, the name corresponding to the pattern
The correspondence itself is a correct probability (hereinafter, referred to as a certainty value) and the like. The rules for this pattern inference are defined in the processing information table 9. In the processing information table 9 shown in FIG. 5, a pattern, a corresponding pattern name, and a method of obtaining a certainty value are described.

For example, assuming that the process “oxidation, film thickness = 1000 °...” In the tenth line of the flow shown in FIG. 6 is the first process, this first process is performed in the process information table shown in FIG. If the condition “(oxidation) and (film thickness ≧ 900 °)” is satisfied, and the process “deposition, film type = silicon nitride, film thickness = 1000 °,...” On line 11 in FIG. This satisfies the condition “(deposition) and (film type = silicon nitride)” in FIG. Similarly, the processing on the 12th to 16th lines in FIG.
Satisfies the condition. At this time, the pattern located in the range of the tenth to sixteenth rows in FIG. 6 satisfies all the conditions of the pattern with the pattern name “element isolation” in FIG. 5 and has the corresponding certainty value “90%” in FIG. Therefore, 10-16 of the flow
The processing information “range = 1” indicating that the pattern in the range in the row has a certainty value of 90% and corresponds to the pattern name “element separation”
Lines 0 to 16, pattern name = element separation, confidence value 90% "
Is generated. FIG. 7 shows an example of processing information generated by the above pattern inference. This processing information is added to the previous process flow information. As described above, in each processing information table, a large number of flows are classified by pattern, and a pattern name indicating each content is given along with its certainty value.

That is, the processing information generation unit 7 uses the processing information table shown in FIG. 5 to correspond the flow shown in FIG. 6 to a series of processing performed by the pattern having the pattern name “element separation” in FIG. It can be shown that the purpose is element isolation with a probability of 90%.

Further, the processing information generation section 7 has a function of imitating the obtained combination of processing information as a pattern again and generating new processing information therefrom again. FIG. 8 shows an example of a processing information table in which rules regarding the pattern inference are defined. In FIG. 8, after defining a method of acquiring processing information regarding two pattern names “P well formation” and “N well formation”, a combination of the two pattern names “P well formation” and “N well formation” A method for acquiring processing information on a new pattern name “well formation” is defined.

For example, when pattern inference is performed from the flow shown in FIG. 9 using the processing information table shown in FIG. 8, first, processing information is generated from a (combination of processing) pattern by the above pattern inference. . That is,
The processing on line 10 in FIG. 9 "Oxidation, film thickness = 1000 °,.
The pattern located in the range from “.” To the processing “peeling, film type = resist,...” On the 14th line in FIG. 9 has a certainty value of 90% and corresponds to the pattern name “P well formation”. Processing information to indicate "range = 10th to 14th line, pattern name = P
Similarly, a pattern located in the range of the 15th to 19th rows in FIG. 9 has a 90% certainty value and corresponds to the pattern name “N well formation”. Processing information shown: “range = line 15 to line 19, pattern name =
N well formation, confidence value = 90% "is generated.

Next, assuming that the generated processing information regarding the pattern name “P well formation” is a first pattern and the processing information regarding the pattern name “N well formation” is a second pattern, the combination of the two processing information is 8, all the conditions of the pattern corresponding to the pattern name "well formation" are satisfied. As a result, the pattern located in the range of the 10th to 19th rows in FIG. Processing information indicating that it corresponds to "formation""range = 10-1"
On the ninth line, “pattern name = well formation, certainty value = 95%” is generated. FIG. 10 shows an example of processing information generated by the above pattern inference.

This pattern inference is repeated until a condition described in an environment information table, which will be described later, is satisfied.
Operations such as change and deletion are performed on the processing information. That is, in the environment information table shown in FIG. 12, the generation end condition “condition (confidence ≧ 95%)” is “the confidence value is 95%”.
% Or more, and the operation "deletion (confidence <95%)" after the condition is satisfied means "deletion of processing information with a confidence value of less than 95%." For example, in the processing information shown in FIG. 11, processing information having a confidence value of less than 95% is deleted from the environment information table shown in FIG.
Only the processing information shown in FIG.

At the time of the above pattern inference, it is the I / O control unit 23 that interprets the method of obtaining each information of the processing information table 9 and the environment information table and actually obtains the information. The unit 7 generates processing information by exchanging information with the I / O control unit 23.

The state information generation unit 11 processes information,
A function for generating state information from the input flow (hereinafter, referred to as
State simulation). Here, the generated state information is, for example, the film configuration of the target object, its film thickness, its shape, and the like. Further, rules regarding this state Michelle are defined in the state information table.

For example, it is assumed that the input flow of the processing information shown in FIG. 13 includes the flow shown in FIG. At this time, the state information table 1 shown in FIG.
The condition “(oxidation) and (thickness> 0 °) and (MOS-FET)” in the right column of No. 3 is satisfied. That is, the 10th line of the flow of FIG. 9 is “(oxidized) and (film thickness = 100
0Å> 0Å), and according to the processing information of FIG. 13, the pattern name in the range 1 to 36th line of the flow is “MOS-FE
T ".

Assume that the state information before the state simulation regarding the processing “oxidation, film thickness = 1000 °,...” On the 10th line in the flow of FIG. 9 is the state information shown in FIG. The state information after the simulation is obtained by adding the state information “film type = silicon oxide, film thickness = specified value” in FIG. 14 to the state information in FIG. At this time, the “designated value” of the state information “film type, = silicon oxide, film thickness = designated value” in FIG. 14 corresponds to the process “oxidation, film thickness = 1000Å,. . ”Is a designated value (condition value) of the condition variable“ film thickness ”of“ 1000 ° ”.

Therefore, the state information after the state simulation regarding the process “oxidation, film thickness = 1000 °,...” On the 10th line in the flow of FIG. The state information after the addition of “silicon oxide, film thickness = 1000 °” is added. FIG. 16 shows an example of the state information after the execution. As described above, the state information generation unit uses the state information table shown in FIG.
State is simulated.

For example, in the oxidation step, the condition value of the condition variable “film thickness” is undetermined, and the condition variables “temperature”,
If only the condition value of “time” is specified, “film thickness”
To know the condition value of, it must be calculated from the condition values of "temperature" and "time". At this time, information such as the oxidation rate (the thickness of the silicon oxide film formed per unit time at a constant temperature) is required. Such necessary information is described in the environment information table.

It is the I / O control unit 23 that interprets the method of obtaining each information of the state information table and the environment information table when the above-mentioned state information is generated, and actually obtains the information. The unit generates state information by exchanging information with the I / O control unit 23.

The output information generator 15 has a function of appropriately checking the contents of the state information obtained by the above-described simulation and generating output information. Rules for this generation are defined in the output information table.

For example, the status information shown in FIG. 19 "film type = aluminum, film thickness = 100 °, position = 20th line,...
“” Indicates the processing “stacking,
The state information after the state simulation regarding “film type = aluminum, film thickness = 100 °,...” Is the condition information “(film type = aluminum) and (film thickness) in the output information table shown in FIG. <200Å) ”, and as a result, the output information“ error content = disconnection, position = 20 lines ”for the state information of FIG. 17 from the output information“ error content = disconnection, certainty value 90% ”in the output information table of FIG. Eyes, 90% confidence value,... FIG. 20 shows an example of the output information. This indicates that the certainty value (probability) that the wiring (aluminum) has a risk of disconnection is 90%.

When generating the output information, it is possible to generate only the output information satisfying a specific condition, for example, only the output information having a certainty value or more as described above. Such conditions are described in the environment information table 21.

When such output information is generated, the method of obtaining the information in the output information table 17 and the environment information table 21 is interpreted, and actual information is obtained by I / O.
The output information generation unit 15 is a control unit 23, and generates output information by exchanging information with the I / O control unit 23.

The output information output unit 19 is provided with an external storage device 20
And a function of outputting to a printer and a display screen via the PC. Further, as shown in FIG. 1, the state information input to the output information output unit 19 is provided by the output information generation unit 15.

The environment information table 21 defines information indicating the operation environment of the flow check device. This information is stored by the user and
Entered by the administrator. FIG. 12 shows an example. At this time, it is the I / O control unit 23 that interprets the method of obtaining each information in the environment information table 21 and actually obtains the information. The information is generated by exchanging the information.

The I / O control unit 23 controls each of the tables 5 to 21
Has a function of interpreting a method of acquiring information and acquiring information. For example, in the state information generation unit 11,
When acquiring numerical information such as the oxidation rate from the environment information table 21, the method of acquiring the oxidation rate in the environment information table 21 shown in the conceptual diagram of FIG.
X, argument 1 = temperature, argument 2 = time) "
The database "X" is searched using the variable values of the condition variables "temperature" and "time" as keywords, and the search result, that is, the oxidation rate is obtained. Then, the state information generating unit 11 receives the oxidation rate from the I / O control unit 23 and generates state information.

Next, means for realizing the present invention will be described with reference to FIG.

Flow storage unit 1, flow conversion unit 3, processing information generation unit 7, state information generation unit 11, output information generation unit 1.
5. The output information output unit 19 and the I / O control unit 23 are realized by a main memory attached to the CPU. Accompanying information table 5, processing information table 9, state information table 13,
The output information table 17 and the environment information table 21 are stored on a recording medium such as a hard disk or a floppy disk. For example, each of the information tables 5 to 21 stored in the recording medium is called into the main memory at the start of the check, and each of the conversion units 3 to 19 and the I / O control unit 23 is controlled by the CPU under software control. Sequentially,
It is implemented sequentially in the main memory attached to the CPU. The processing result is output to a printer and a display screen via the external storage device 20.

Next, the operation of the present invention will be described with reference to FIG.

The flow storage unit 1 loads a flow from a storage device into a main memory of a computer. FIG. 6 shows an example of the flow. In the drawing, codes representing the type of processing, condition variables, and condition variable values are described in the order of processing steps. One line of the flow corresponds to one process.

The flow converter 3 adds missing information and simplified information to the flow taken into the main memory. The method of acquiring the generated information is managed by the accompanying information table 5, interpreted by the I / O control unit 23, and the information is acquired. By performing this operation, it is possible to reduce information to be input at the time of creating a flow, and it is possible to greatly simplify the creation of a flow. In addition, it is possible to handle a large amount of data.

In the processing information generating section 7, the pattern name corresponding to the pattern, the range in which the pattern exists in the flow, and the correspondence are accurately determined from the flow converted by the flow converting section 3 with a certain degree of probability. Processing information indicating a certainty value indicating whether or not the processing information is generated. The method of obtaining the information to be generated is managed by the processing information table 9 and interpreted by the I / O control unit 23 to obtain the information. Further, the termination condition of the pattern inference and the operation after the condition is satisfied are managed by the environment information table 21, and the I / O control unit 2
3 and the information is obtained. here,
By generating processing information, patterns are classified by purpose, content, and meaning. By performing this work, it is possible to perform a check / simulation depending on the purpose, contents, and meaning.

The state information generator 11 generates state information indicating the state of the film configuration, the film thickness, the shape, and the like of the object from the processing information generated by the processing information generator 11. The method of obtaining the generated information is managed by the state information table 13 and interpreted by the I / O control unit 23 to obtain the information. Further, necessary information such as the above-described oxidation rate is managed by the environment information table 21 and interpreted by the I / O control unit 23 to obtain information. Here, by generating state information,
The simulation of the state transition of the object is performed. Here, since the patterns are already classified according to purpose, content, and meaning, it is possible to perform only the minimum necessary state simulation.

The output information generation unit 15 appropriately checks the status information generated by the status information generation unit 11 and generates output information. The method of acquiring the information to be generated is managed by the output information table 17, and the I / O control unit 2
3 to obtain information. In addition, necessary information such as the minimum confidence value of the information to be output is managed by the environment information table 21, interpreted by the I / O control unit 23, and the information is acquired. Here, the flow is checked based on the purpose, contents, and meaning by generating the output information. Since this state information is generated as a result of performing only necessary simulations, and necessary information such as the minimum confidence value of the information to be output is described in the environment information table 21. Only the minimum necessary output information generation (check) can be performed.

In the output information output section 19, the output information generation section 1
The output information generated in 5 is output to the external storage device 20.

Next, the flow of information will be described with reference to FIG.

First, the flow in the storage device is stored in the main memory by the flow storage unit 1, and then the missing information and the simplified information are added by the flow conversion unit 3. . From the converted flow, processing information is generated (pattern inference) by the processing information generating unit 7, whereby the flow (pattern) has the purpose,
Classified by content and meaning. Next, the state information generation unit 11
As a result, state information is generated (state simulation) from the flow and the processing information, whereby the flow is simulated depending on the purpose, content, and meaning of each processing. Finally, the output information is generated by the output information generation unit 15 from the state information. This checks the contents of the flow, and the result (output information) is output to the output device by the output information output unit.

As described above, in the process flow check / simulation apparatus of the present invention, each information is generated using each information table, so that the flow described in the processing order can be checked / simulated at high speed. Becomes

[0054]

As described above, in the process flow check / simulation apparatus according to the present invention, the check / simulation of the process flow is performed by the computer. As a result, the know-how of a conventionally experienced expert can be easily used as common knowledge by anyone from personal property. Although it is inevitable that human errors increase with the increase in the number of processing steps, the computer eliminates careless mistakes in checking. Also, know-how of check simulation depending on the purpose, contents, and meaning of this processing, which was conventionally difficult to perform by a computer, can be used.

[Brief description of the drawings]

FIG. 1 is a functional configuration diagram of a process flow check / simulation apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of an accompanying information table.

FIG. 3 is a diagram showing an example of a flow for explaining a flow conversion unit 3;

FIG. 4 is a view showing a conversion result of the flow of FIG. 3 by the accompanying information table 5 of FIG. 2;

FIG. 5 is a diagram showing an example of a processing information table 9;

FIG. 6 is a diagram showing an example of a flow for explaining a processing information generation unit 7;

FIG. 7 is a view showing processing information generated from the flow of FIG. 6 by the processing information table of FIG. 9;

FIG. 8 is a diagram showing an example of a processing information table 9.

FIG. 9 is a diagram showing an example of a flow for explaining a processing information generation unit 7;

FIG. 10 is a view showing an example of processing information generated from the flow of FIG. 9 by the processing information table 9 of FIG. 8;

FIG. 11 is a diagram showing an example of processing information for explaining a processing information generation unit 7;

FIG. 12 is a diagram showing an example of an environment information table 21.

FIG. 13 is a view showing processing information generated from the processing information of FIG. 11 by the environment information table 21 of FIG. 12;

FIG. 14 is a diagram showing an example of a state information table 13;

FIG. 15 is a diagram showing an example of state information for explaining the state information generation unit 11;

FIG. 16 is a diagram showing status information generated from the status information of FIG. 15 by the status information table 13 of FIG. 14;

FIG. 17 is a diagram showing an example of an output information table 17;

FIG. 18 is a diagram showing an example of a flow for explaining the output information generation unit 15;

FIG. 19 is a diagram showing an example of state information for explaining the output information generation unit 15;

20 is a diagram showing output information generated from the state information of FIG. 19 by the output information table 17 of FIG. 17;

FIG. 21 is a conceptual diagram for explaining an I / O control unit 23;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flow storage part 2 Storage device 3 Flow conversion part 5 Associated information table 7 Processing information generation part 9 Processing information table 11 State information generation part 13 State information table 15 Output information generation part 17 Output information table 19 Output information output part 20 External storage Device 21 Environment information table 23 I / O control unit

Claims (3)

(57) [Claims] 1. A flow storage unit for storing a process flow consisting of a series of processing conditions, a processing information table for storing information on the contents of processing in association with each processing condition, and a processing information table stored in the flow storage unit. A processing information generating unit that generates information on the contents of the processing conditions stored in the flow storage unit based on a comparison between the processing conditions and the processing conditions corresponding to the processing information stored in the processing information table. A state information generation unit that simulates a processing state of a previous process flow based on the information generated by the processing information generation unit, an output information table that stores information about an error accompanying processing contents, and the processing information Based on a comparison between the content of the simulation performed by the generation unit and the information stored in the output information table, the flow model A process flow check / simulation device, comprising: an output information generation unit that outputs an error of a processing condition stored in a storage unit. 2. The process flow check method according to claim 1, wherein the process information table has a correspondence between a specific combination of a plurality of process conditions and a content of a process achieved by the combination. Simulation device. 3. An accompanying information table for storing a condition associated with a specific processing condition or a method for acquiring the condition, and a processing condition stored in the flow storage unit based on the contents of the accompanying information table. 2. The process flow check / simulation device according to claim 1, further comprising: a flow conversion unit that adds