JPH06283498A - Semiconductor production device - Google Patents

Abstract

PURPOSE:To obtain a wet etching device capable of controlling foreign matters in chemicals on an in-line basis. CONSTITUTION:An in-liquid dust counter 9 is juxtaposed to a conventional etching tank, and foreign matters in chemicals 1 in the etching tank can be measured at all times. Consequently, foreign matters in chemicals 1 can be controlled on an in-line basis. Accordingly, the foreign matters of wet etching are controlled on an in-line basis. Thus manufacturing a semiconductor device having high yield and high quality.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus for manufacturing ICs and LSIs by wet etching.

[0002]

2. Description of the Related Art The structure of a conventional semiconductor manufacturing apparatus will be described with reference to FIG. FIG. 5 is a diagram showing a conventional semiconductor manufacturing apparatus.

In FIG. 5, 1 is a chemical liquid such as BHF liquid and HF liquid, 2 is a pipe such as a Teflon tube through which the chemical liquid 1 circulates, 3 is a pump for circulating the chemical liquid 1, 4 is a foreign matter removing device. Filter 5 is an inner tank of an etching tank for etching, 6 is an outer tank of the etching tank for storing the chemical solution 1 overflowing from the inner tank 5, 7 is a basket containing a silicon wafer, and 8 is silicon for etching. It is a wafer.

Next, the operation of the conventional semiconductor manufacturing apparatus will be described with reference to FIG. First, the silicon wafer 8 to be etched is placed in the basket 7 and immersed in the inner tank 5 for etching. Then, after soaking in the chemical solution 1 for a predetermined time, the basket 7 is placed in a washing tank (not shown).
After removing the chemical liquid 1 by putting in, the product is dried to complete the etching. The pattern formation of the film to be etched is performed by wet etching in this procedure.

However, in the inner tank 5 of the etching tank, many foreign materials such as foreign materials brought in from the silicon wafer 8 and reaction products generated by etching are accumulated. Therefore, since the inner tank 5 of the etching tank is formed so as to overflow, foreign matters also overflow and move to the outer tank 6. And the drug solution 1 that overflowed
Is passed through the pipe 2 by the pump 3, passes through the pump 3 and the filter 4, and returns to the inner tank 5. At this time, the foreign matter is removed by the filter 4, and the chemical liquid 1 free from the foreign matter is supplied to the inner tank 5. And
By repeating this circulation, the foreign matter in the etching bath is reduced.

[0006]

In the conventional semiconductor manufacturing apparatus as described above, the chemical liquid 1 is circulated through the filter 4 to reduce foreign matters.
However, there was a problem that the number of foreign substances could not always be managed inline.

The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to obtain a semiconductor manufacturing apparatus capable of managing foreign substances of a chemical solution in-line and also managing a filter. To do.

[0008]

A semiconductor manufacturing apparatus according to the present invention comprises the following means. [1] Counting means for measuring the number of foreign substances in the chemical liquid. [2] Calculation means for obtaining the foreign matter recovery characteristic based on the number of foreign matter. [3] Alarm means for outputting an alarm to that effect when the foreign matter recovery characteristic obtained by the above calculation is worse than the reference characteristic obtained in advance.

[0009]

In the semiconductor manufacturing apparatus according to the present invention, the number of foreign substances in the chemical liquid is measured by the counting means. Further, the foreign matter recovery characteristic is obtained by the computing means based on the number of foreign matter. When the foreign matter recovery characteristic obtained by the above calculation is worse than the reference characteristic obtained in advance, the alarm means outputs an alarm to that effect.

[0010]

EXAMPLES Example 1. The configuration of the first embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Figure 1
FIG. 3 is a diagram showing Embodiment 1 of the present invention. Also, FIG.
FIG. 3 is a block diagram showing a control device of Embodiment 1 of the present invention.

In FIG. 1, 1 is a chemical liquid such as BHF liquid and HF liquid, 2 is a pipe such as a Teflon tube through which the chemical liquid 1 circulates, 3 is a pump for circulating the chemical liquid 1 and 4 is a foreign matter removing device. Filter 5 is an inner tank of an etching tank for etching, 6 is an outer tank of the etching tank for storing the chemical solution 1 overflowing from the inner tank 5, 7 is a basket containing a silicon wafer, and 8 is silicon for etching. It is a wafer.

Further, in FIG. 1, 9 is a submerged dust counter for obtaining the number of foreign substances based on the reflected light of the foreign substances by an optical means such as a laser, 10 is a control device connected to the submerged dust counter 9, and 11 is a control unit. An alarm device connected to the device 10. In each figure, the same reference numerals indicate the same or corresponding parts.

In FIG. 2, the control device 10 includes a ROM,
It is composed of a CPU, a RAM, and the like.

By the way, the counting means of the present invention corresponds to the submerged dust counter 9 in the first embodiment, and the computing means of the present invention corresponds to the control device 10 in the first embodiment, and the alarm means of the present invention. Is the alarm device 1 in the first embodiment.
Equivalent to 1.

The operation of the first embodiment of the present invention will be described with reference to FIGS. 3 and 4. FIG. 3 is a flowchart showing the operation of the first embodiment of the present invention. Also, FIG.
FIG. 4 is a diagram showing a foreign matter recovery characteristic according to the first embodiment of the present invention.

The chemical liquid 1 used for etching and sent to the filter 4 is sent to the submerged dust counter 9 through the bypass pipe 2 so that foreign substances can be constantly measured. At this time, when the etching is performed, the number of foreign matters shows a recovery characteristic that the number of foreign matters increases sharply when the silicon wafer 8 is pulled up and decreases with the passage of time as shown in FIG. Since the recovery characteristic of the foreign substance number is peculiar to each chemical liquid 1, the foreign substance number recovery characteristic permissible angle θ ₀ in a good state of the chemical liquid 1 is set in advance, and the recovery characteristic angle becomes larger than the permissible angle. When the foreign matter number recovery characteristic alarm angle θ
In a), an alarm is set to sound using this foreign matter recovery characteristic.

The control device 10 for controlling the foreign matter in the chemical liquid 1 is
It can be composed of a microcomputer programmed as described above. That is, this control device 1
As shown in FIG. 2, 0 has a CPU, a ROM in which a program is stored, and a RAM in which control data is stored. When data of the submerged dust counter 9 is input, the CPU 0 performs arithmetic processing. , Sends a control output signal to the alarm device 11.

The control data stored in the RAM is
The foreign matter number recovery characteristic allowable angle θ ₀ . When controlling the foreign matter according to the first embodiment, an alarm is issued when the calculation result of the output value from the submerged dust counter 9 becomes larger than the foreign matter number recovery characteristic allowable angle θ ₀ .

Next, the operation of the control device 10 will be described with reference to the flowchart shown in FIG. First, in step 30, the foreign matter number recovery characteristic allowable angle θ _{0 and the} like are stored in the RAM and initialization is performed.

In step 31, the linear regression line logN = a (t-t) is obtained from the data of the submerged dust counter 9.
o) + b is calculated. Here, N is the number of foreign matters counted by the submerged dust counter 9, t is time, and to is maximum foreign matter (N
_MAX ) time. Note that b = logN _MAX .

In step 32, θ = tan ^-1 a is calculated.

In step 33, the previous step 32
And the initial set value of the foreign matter number recovery characteristic allowable angle θ ₀
If θ ≧ θ ₀ , an alarm is issued in step 34, otherwise the process returns to step 31 and the processes from step 31 to step 33 are repeated.

As described above, the foreign matter can be controlled in-line, and the semiconductor device with high yield and high reliability can be manufactured. This device can also be used to manage the filter 4.

The first embodiment of the present invention, as described above,
A submerged dust counter 9 is provided so that the number of foreign substances in the chemical liquid 1 can be constantly measured, and foreign substances and filters 4 can be managed in-line. The foreign matter management characteristic during etching as shown in FIG. 4 is utilized to enable foreign matter management inline.

That is, according to the first embodiment of the present invention,
During the etching by the submerged dust counter 9,
The foreign matter can be measured, and the foreign matter of the etching liquid is controlled in-line to obtain a high quality and highly reliable wet etching apparatus.

[0026]

As described above, the semiconductor manufacturing apparatus according to the present invention comprises counting means for measuring the number of foreign substances in a chemical solution,
Since the foreign matter recovery characteristic is calculated based on the number of foreign matter and the foreign matter recovery characteristic obtained by the calculation is worse than the previously determined reference characteristic, an alarm means for outputting an alarm to that effect is provided. It is possible to manage foreign substances and also manage filters.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing a control device according to the first embodiment of the present invention.

FIG. 3 is a flowchart showing the operation of the first embodiment of the present invention.

FIG. 4 is a diagram showing foreign matter number recovery characteristics according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a conventional semiconductor manufacturing apparatus.

[Explanation of symbols]

 1 Chemical Solution 2 Piping 3 Pump 4 Filter 5 Inner Tank of Etching Tank 6 Outer Tank of Etching Tank 7 Wafer Basket 8 Silicon Wafer 9 Liquid Dust Counter 10 Controller 11 Alarm

Claims (1)

[Claims] 1. A counting unit for measuring the number of foreign substances in a chemical solution, a calculating unit for obtaining a foreign substance recovery characteristic based on the number of foreign substances, and a foreign substance recovery characteristic obtained by the calculation when it is worse than a reference characteristic obtained in advance. A semiconductor manufacturing apparatus comprising an alarm means for outputting the alarm.