JPH081883B2 - Semiconductor process flow creation system - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for creating a process flow that defines a procedure for sequentially processing a plurality of unit processes, and is mainly applied to a semiconductor process. Is.

2. Description of the Related Art A semiconductor process is different from other general manufacturing processes in that a process step in the same apparatus is repeated many times from the introduction of a certain lot to the completion thereof. If any device is passed only once, the lot flow line is a simple line. However, in the semiconductor process, the flow line of the lot is extremely complicated, and changes depending on the product.

In addition, the number of unit processes in one lot is increasing until the device is completed with the miniaturization and high integration of design dimensions, and the number reaches 100 to 200 processes.

A process flow is created when a large number of lots are flown in the process of product development. However, due to the above background, misunderstanding and carelessness may be caused, and an erroneous process flow leading to a lot defect may be created.

Conventionally, the countermeasures have mainly relied on the attention of engineers.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention not only creates an erroneous process flow and makes the lot defective, but also puts it in a thermal oxidation process requiring cleanliness after applying a photoresist, for example. This is to solve the conventional problem that the electric furnace is contaminated and seriously adversely affects other lots.

Means for Solving the Problems The present invention includes a process flow memory group, which is a set of memories in which a plurality of unit process names are stored in a processing order for one lot, and a process flow memory group exists immediately before or after each specific unit process. Matches the sequence rule memory group, which is a set of memories storing the required process names that should be present and the prohibited process names that should not exist, with the unit process in the process flow memory group and the process name in the sequence rule memory group. A system configuration having a presence detection circuit that detects a mismatch and a rule matching circuit that includes first and second accumulators.

Action Sequence Flow regarding the jth unit step of a memory in the process flow memory group (PFM) Searches for the existence of the memory in the memory group (SRM), and if there is, the required process name in that memory and The forbidden process names are sequentially read out, and the (j-1) th or (j-1) th in the PFM is read.
+1) If there is a match with the unit process, "1" is output from the existence detection circuit if there is no match, and the first accumulator in the rule matching circuit outputs the required process name only to the first accumulator. The coincidence output signal is added to the second accumulator only when the process name is prohibited, and as a result of the addition for all steps of the memory in the SRM for the jth unit step, the result of the first accumulator is added. If the output is zero, the essential process missing signal is output, and if the output of the second accumulator is not zero, the prohibited process deletion signal is output.

Embodiment FIG. 1 shows the basic configuration of an embodiment system of the present invention.

Process information such as process name (KP NAME) for each unit process, condition parameter name and its default value is recorded in each record (R1, R
2, R3 ...), an arbitrary record is selected from the unit process memory 1 stored by the input selection circuit 2 and transferred to the process flow memory (PFM) 3. The PFM3 is composed of a memory (PFM) 31, 32, 33 ... Which stores information for each lot. A process flow is created by storing unit process names in a certain memory, such as PFM31, in the order of processing. The unit process name in the designated register in PEM3 is read by the selection circuit 4 to the presence detection circuit 7.

The information of the sequence rule memory (SRM) group 5 which is a set of memories 51, 52, 53, etc. in which the sequence rules are written for each specific unit process is input by the selection circuit 6 to the other input of the rule existence detection circuit 7. Become.

One memory 51 of the SRM has sequence rule information regarding a specific unit process. For example, the first
In the line (R1), the name of the unit process to be noted (target process name) is written. The essential process name that must exist immediately before or after the process of interest or the prohibited process name that must not exist is the second
Written below line (R2). Each record (R2, R3 ...) on and after the second line consists of at least two digits and a unit process name. In this example, a two-digit number is assigned to the first and second columns (C1 and C2) of each record. These digits C1 and C2 are used to express the sequence rule. For example, C1 = “0”: Process immediately before the process of interest (PRE) “1”: Process related to the process immediately after the process of interest (POST), and C2 = “0”: Process that does not exist (NOT) “1”: Indicates that it is a mandatory process (MUST). FIG. 2 shows four rules based on this combination.

1st and 2nd in each record (R2, R3 ...) below the 2nd line
The columns C1 and C2 represent the rules, and the third and subsequent columns (C3, C4 ...) Represent the unit process names (EP NAME) to be the rules.
For example, the first record R1 = EP007 and the second record R2 = 10E
When it is P035, EP035 must not be present immediately after the attention process (R1) EP007. That is, it is prohibited to include the processing procedure of [EP007] → [EP035] in the process flow. This corresponds, for example, to the case where EP007 is the resist developing step and EP035 is the high temperature oxidation step.

Now, in order to check whether or not the process flow created in PFM is correct in light of such a sequence rule written in SRM, the rule existence detection circuit 7 and the output from it are accumulated. A rule matching circuit 12 including an accumulator ACCM1 and an accumulator ACCM0 for is included in the system.

Specify one lot, ie one PFM, eg PFM31. Next, pay attention to the unit processes in the sequence order in the PFM 31, and check whether the processes before and after the process match the sequence rule.

Attention is now paid to the j-th unit process in PFM31. That is SRM
Check whether all SRM is written in R1 in
Suppose that it was written in SRM51, that is, there was a sequence rule (if not, then pay attention to the j + 1th unit process). Although it is necessary to examine the rules immediately before and immediately after the j-th step, first, let us examine the rule immediately after. So (j + in PFM31
The selection circuit 4 inputs the 1) th unit process name to one of the detection circuits 7. At that time, the records R2, R3, ... Of the SRM51 are sequentially input to the other of the detection circuits 7 by the selection circuit 6, and if the unit process names of the two coincide with each other, "1" is output, and if they do not coincide, "0" is output from the detection circuit 7. Output. However, at the present time, the records fetched by the selection circuit 6 are only those having C1 = "1". The output signal from the detection circuit 7 is added to the accumulator ACCM1 or ACCM0 via the switch transistor 8 or 10. For the switch transistor 8 or 10, the value in the second column C2 of the SRM51 is "1".
When (presence is required) and when it is “0” (presence is not present), it is opened, and the accumulators ACCM1 and ACCM0 have
The number of times the existence mandatory rule is satisfied and the number of times the existence prohibition rule is violated are recorded (see FIG. 3). SR
Since the unit process name written in each record in M51 can be the same, the existence mandatory rule can be satisfied only once. Even after accumulating over records, there is only a value of 1 or 0. Even if the mandatory rules for existence are R4 and R5 and two steps are written, it is not possible to satisfy both of them at the same time, and only one of them should be satisfied. On the other hand, the existence prohibition rule must not violate any of the two steps, R2 and R3.

Therefore, the accumulation result for all records in SRM51, A
If CCM1 is not zero, the existence mandatory rule is satisfied (OK), and if ACCM0 is zero, the existence prohibition rule is satisfied (OK), which means that all sequence rules are satisfied. The process (C1 = 0; j-1) immediately before is investigated. However, if ACCM1 is zero, the existence essential rule is not satisfied, so "missing warning signal W1 of essential process"
Is output. If ACCM0 is 1 or more, the existence prohibition rule is not satisfied. Therefore, the “prohibition process deletion warning signal W0” is output, and the PFM31 is in the correction waiting state. Alternatively, the warning signal may be written by preparing a memory for storing a specific rule check result.

EFFECTS OF THE INVENTION According to the present invention, by preparing in advance the sequence relation between each unit process in the process flow as a sequence rule, it is possible to prevent an inadvertent mistake when connecting arbitrary unit processes in series. Can be done.

Therefore, the correct process flow is created, and not only the lot definitely flows, but also the contamination of the device due to a mistake can be prevented and other lots will definitely flow, which contributes to the improvement of the efficiency of the whole process. is there.

[Brief description of drawings]

FIG. 1 is a system diagram of an embodiment showing a basic configuration of the present invention, FIG. 2 is a diagram showing a sequence rule, and FIG. 3 is a diagram showing rule matching conditions. 1 ... Unit process memory, 2 ... Input selection circuit, 3 ...
Process flow memory group, 4,6 …… Selection circuit, 5 ……
Sequence rule memory group, 7 ... rule existence detection circuit, 9,11 ... accumulator, 12 ... rule matching circuit.

Claims (1)

[Claims] 1. A process flow memory group, which is a set of memories in which a plurality of unit process names are stored in a processing order for one lot, and an essential process name that should exist as a process immediately before or immediately after a specific unit process. The sequence rule memory group, which is a set of memories in which prohibited process names that must not exist, and the process name in the sequence rule memory group are searched for the jth unit step of a memory in the process flow memory group. , (J-1)
A rule presence detection circuit that detects a match / mismatch with the th or (j + 1) th unit process name, and a first accumulator that adds a match output signal from the above presence detection circuit only when the process name is essential A rule collating circuit including a second accumulator that adds only when the process name is present, and the output of the first accumulator for all process names in the sequence rule memory group for the j-th unit process is zero. Then, the semiconductor process flow creation system configured to output the essential process missing signal and the prohibited process deletion signal unless the output of the second accumulator is zero.