JPH03173114A - Manufacture of semiconductor - Google Patents

Abstract

PURPOSE:To highly clean the inside of a semiconductor manufacturing facility for performing one or a plurality of processes of manufacture of a semiconductor device, to remove contaminant generated in an apparatus, and to improve reliability and yield by providing gaseous impurity removing means for clarifying its working atmosphere in the facility. CONSTITUTION:In an example of a wafer transfer facility, gaseous impurity removing means 3 is provided under an air inlet passage 1, and a conveyor belt 4 of a wafer 5 is mounted thereunder. In the means 3, filter electrodes 9, 11 used also as filters and duct collecting electrodes are arranged at a predetermined interval and grounded, and a DC power source 12 for applying a bias voltage is connected between a filter electrode 10 and the ground. If a voltage is applied to the electrode 10, a high voltage is applied between the electrodes 10 and 9, 10 and 11, and dust is removed when the air is passed through the electrodes 9, 11. Charged particles in the air are attracted to the electrode by static electricity formed between the electrodes, and ionized impurities are converted into neutral gas.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a technology for keeping the manufacturing atmosphere of semiconductor devices clean;
In particular, the present invention relates to a technique that is effective when used to maintain a high level of air cleanliness in a manufacturing atmosphere.

[Conventional technology]

For example, in the manufacturing process of semiconductor integrated circuit devices, if dust in the work space adheres to the semiconductor substrate on which fine circuit patterns are formed, it can cause fatal defects in the semiconductor integrated circuit devices that are formed. .

For this reason, for example, Kogyo Kenkyukai Co., Ltd., 19861
Published on January 18th, “Electronic Materials J 1986 Special Issue P17
6 to P188, the air in the work atmosphere shielded from the outside is treated with HEPA (lligh efficiency).
Particulate air is passed through a filter or the like to remove dust and the like floating in the working atmosphere, and the purified air is introduced into the working atmosphere.

By the way, the present inventor studied air cleaning in a working atmosphere in a semiconductor manufacturing process.

The following are the techniques studied by the present inventor, and the outline thereof is as follows.

That is, in general, 510
The air flow passes through a filter medium in which filamentous oxides mainly composed of
A HEPA filter is used to reduce the amount of air in the air, e.g.
．． Fine particles of about 1 μm are captured by physical adsorption at room temperature.

In addition, there are systems in which the high-cleanliness area is unitized, and the required number of units can be connected according to the process length, so that the volume of the working atmosphere can be freely increased or decreased (for example, Hitachi Refrigeration Co., Ltd., "Clean Tunnel" described in the catalog "Hitachi Environmental Control System Equipment").

[Problem to be solved by the invention]

However, in semiconductor manufacturing equipment using HEPA filters as described above, the limit of particle removal is about 0.1 μm, so it is difficult to remove gaseous impurities (ions, molecules such as halogens, atoms) smaller than this. The inventor has discovered that there are problems listed below, for example.

(1) Occurrence of dielectric breakdown and edge deterioration due to capacitance of microstructure.

(2) Fluctuations in electrical characteristics due to impurities in the gate oxide film.

(3) Corrosion, defects, and deterioration of the surface of materials (wiring, gates, etc.).

If these problems are not solved, it is expected that in the future large-capacity memories will require wiring processing of about 0.3 μm, but it is not possible to solve the above problems for such miniaturization. required.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a technique that can remove gaseous impurities from a working atmosphere.

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

[Means to solve the problem]

A brief overview of typical inventions disclosed in this application is as follows.

That is, the configuration includes semiconductor manufacturing equipment that is in charge of one or more processes in the semiconductor manufacturing process, and gaseous impurity removal means that cleans the working atmosphere of the semiconductor manufacturing equipment.

[Effect]

According to the above-mentioned means, by providing a gaseous impurity removal means in the air flow path or inside of the semiconductor manufacturing equipment,
Gaseous impurities present or generated in the working atmosphere of semiconductor manufacturing equipment are effectively removed. Therefore, various problems caused by gaseous impurities are solved, and reliability and yield can be improved.

[Embodiment 1] FIG. 1 is a schematic front view showing one embodiment of a semiconductor manufacturing apparatus according to the present invention, FIG. 2 is a schematic configuration diagram showing details of the gaseous impurity removing means of FIG. 1, and FIG. The figure is an external perspective view showing another example of the gaseous impurity removing means.

FIG. 1 shows an example in which the semiconductor manufacturing equipment is a wafer transport equipment for manufacturing semiconductor devices. Air discharged from the outside or from the device is supplied from above, and an air introduction path 1 for taking in this air is formed at the top. A pressurized fan 2 is installed in the air introduction path 1 to forcibly blow the introduced air downward.

A gaseous impurity removing means 3 for removing gaseous impurities from the air supplied by the pressurized fan 2 is installed at the lower part of the air introduction path 1 .

A conveyor belt 4 that conveys the wafer 5 horizontally at a predetermined interval is rotatably installed below the gaseous impurity removing means 3. The conveyor belt 4 is mounted on a drive roller 6 and a driven roller 7.

The periphery of this driven roller rough forms a wafer transfer area 8.

As shown in FIG. 2, the gaseous impurity removing means 3 includes a filter electrode 9 that is made to allow air to pass through and remove dust and has the functions of both a filter and a dust collecting electrode, and a filter having a similar configuration. Filter electrodes 9 having the same configuration as the electrode 10 and the filter electrode If are arranged at predetermined intervals so as to close the passage. Among these filter electrodes, the filter electrode 9 and the filter electrode 11 that constitute the first filter electrode are grounded, and a predetermined bias is applied to the filter electrode 10 between the filter electrode 10 that constitutes the second filter electrode and the ground. A DC power supply device 12 for applying voltage is connected.

As the filter electrode 9 and the filter electrode 11, in addition to a conductive filter, a filter made of conductive polymer or the like can be used.

In FIG. 2, when a predetermined voltage is applied to the filter electrode 10 and air is supplied from a direction A in the figure by an unillustrated blower or the like, the filter electrode 10, the filter electrode 9, and the filter electrode 10 A high voltage is applied between each of the filter electrodes 11, and when air passes through the filter electrodes 9 and 11, denitrification is performed by the filter function. Further, charged particles in the air passing through the filter electrode 9.11 are adsorbed to the surface of the electrode due to the static electricity formed between the electrodes. Also, ionic impurities in the air are turned into a neutral gas.

FIG. 3 shows another example of the structure of the gaseous impurity removing means 3.

The main body 13 is made of a plate-like thermally conductive material, and is folded into an S-shape in the thickness direction with a predetermined width and gap, so that a large surface area can be obtained in a small space. A plurality of temperature control tubes 14 are disposed to penetrate the entire body 13 in the thickness direction. This temperature control tube 14
In each of the heating medium 1 whose temperature is controlled in advance to a desired temperature,
5 is supplied. Furthermore, a plurality of types of adsorbents 16 and 17 are adhered to the surface of the main body 130 over almost the entire surface thereof, depending on the type of gaseous impurity (or vaporous impurity) to be adsorbed.

In the gaseous impurity removing means 3 having such a configuration,
The temperature of the heat medium 15 flowing through the temperature control pipe 14 is made lower than the temperature in the working atmosphere. As a result, B
Gaseous impurities contained in the air supplied from the
It is adsorbed by adsorbent materials 16 and 17 attached to the main body 13.

In this case, since the surface area of the adsorbent 16, 17 is limited, after a predetermined operating time has elapsed, a regeneration process is required to desorb the gaseous impurities that have already been adsorbed. Therefore, the temperature of the heat medium 15 flowing inside the temperature control tube 14 is made higher than that during adsorption. This allows the adsorbent 16.1
The gaseous impurities that had been stably adsorbed on the surface of the adsorbent 7 are removed from the adsorbent 16 and 17, and the regeneration process is completed in a relatively short time.

In addition to the configuration shown in FIG. 3, a configuration may be adopted in which the vibrator is piped so that the temperature control medium flows around the main body 13. Alternatively, a structure may be adopted in which a pipe through which a temperature control medium flows is arranged in a meandering manner inside a filter medium using a good thermal conductor.

As described above, gaseous impurities contained in the taken in air could not be removed conventionally, but according to the present invention, gaseous impurities are removed before the wafer transfer area 80 by the gaseous impurity removing means 3. .

Therefore, impurities generated as the transport belt 4 rotates can be discharged from the apparatus without entering the wafer transport area 8. Moreover, ionic impurities are not attached to the wafer. Therefore, it is possible to improve product yield.

[Embodiment 2] FIG. 4 is a schematic front view showing a second embodiment of the present invention. In addition, in FIG. 4, the same reference numerals are used for the same parts as used in FIG. 1, so a redundant explanation will be omitted below.

This embodiment is an example in which the semiconductor manufacturing equipment is a baking furnace that heats resist applied to a wafer. The baking oven 18 has a heater 20 installed at the bottom for heating the wafer 19, a gaseous impurity removing means 3 on one wall, and an exhaust port 21 on one of the other walls. A pressurized fan 2 is installed at a location upstream of the gaseous impurity removing means 3. The gaseous impurity removing means 3 shown in FIG. 2 or 3 is used.

In this embodiment, the introduced air is forced into the gaseous impurity removing means 3 by the pressurized fan 2, and gaseous impurities in the air are removed while passing through the gaseous impurity removing means 3. The solvent generated in the baking furnace 18 during the beta process is discharged from the exhaust port 21 so as to be replaced by clean air supplied from the gaseous impurity removing means 3. Therefore, the inside of the baking furnace 18 is highly cleaned,
Impurities are not attached to the resist surface of the wafer 19.

[Embodiment 3] FIG. 5 is a schematic front view showing a third embodiment of the present invention. In addition, in FIG. 5, the same reference numerals are used for the same parts as used in FIG. 1, so a redundant explanation will be omitted below.

This example is an example of equipment for forming a thin film by introducing a reactive gas into a chamber in a vacuum atmosphere.

A shutter 23 is installed at the bottom of the chamber 22 to seal the inside of the chamber 22 after the reaction gas is introduced. A gaseous impurity removing means 3 is installed outside the shutter 23, and a pressurized fan 2 is installed on the air input side of the gaseous impurity removing means 3. Further, an exhaust port 24 is formed near the bottom of the chamber 22 to exhaust the supplied air and the used reaction gas.

In this embodiment, before the semiconductor device is processed, the shutter 23 is opened and the pressurized fan 2 is driven to supply purified air into the chamber 22.

At the same time, the chamber 22 is filled with purified air while being exhausted from the exhaust port 24.

Thereafter, the shutter 23 is closed, air is removed through the exhaust port 24, the chamber 22 is evacuated, and processing operations such as thin film formation are performed. As a result, residual gases, reaction products, unreacted gases, etc. generated by the reaction in the previous treatment can be discharged, thereby providing a work environment with less pollution.

[Embodiment 4] FIG. 6 is a schematic circuit diagram showing a fourth embodiment of the present invention.

This embodiment is an example in which the semiconductor manufacturing equipment is a high-frequency sputter system. A wafer 27 is set on the electrode 26 and is grounded. A high frequency power supply device 28 is connected between the electrodes 25 and 26.

A filter electrode 29 is provided as gaseous impurity removing means 3 so as to surround the wafer 27 . Furthermore, a DC power supply device 31 is connected to the filter electrode 29 and the electrode 26 .

In the embodiment of FIG. 6, the wafer 27 is placed on the electrode 26.
and fill the working atmosphere with inert gas (argon).
is introduced to drive the high frequency power supply device 28 and the DC power supply device 31. Then, argon ions collide with the wafer 27 on the electrode 26 by the high frequency power supply 28, and the wafer 2
The natural oxide film on 7 pops out in the form of atoms, and that part is etched away. On the other hand, ionized atoms (impurities) ejected from the wafer 27 are adsorbed and removed by the filter electrode 29 and the electrode 26 driven by the DC power supply 31.

In the past, the impurity atoms scattered from the wafer 27 were released into the working atmosphere, which caused the above-mentioned problems. However, according to the present embodiment,
Since it can be removed during the sputtering process, various problems caused by redeposition of atoms can be solved.

In the configuration shown in FIG. 6, the gaseous impurity removing means 3 shown in FIG. 2 may be installed in the vacuum evacuation system.

As above, the invention made by the present inventor has been specifically explained based on examples, but the present invention is not limited to the above-mentioned examples, and various modifications can be made without departing from the gist thereof. Needless to say.

〔Effect of the invention〕

Among the inventions disclosed in this application, the effects obtained by typical ones are as follows.

In other words, by providing semiconductor manufacturing equipment that handles one or more processes in the manufacturing process of semiconductor devices and gaseous impurity removal means that cleans the working atmosphere of the semiconductor manufacturing equipment, the interior of the semiconductor manufacturing equipment can be kept highly clean. Furthermore, it becomes possible to remove contamination generated within the device, thereby improving reliability and yield.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view showing an embodiment of a semiconductor manufacturing apparatus according to the present invention, FIG. 2 is a schematic configuration diagram showing details of the gaseous impurity removing means in FIG. 1, and FIG. 3 is a gaseous impurity removing means. 4 is a schematic front view showing a second embodiment of the present invention; FIG. 5 is a schematic front view showing a third embodiment of the present invention; 6111i is a main FIG. 7 is a schematic circuit diagram showing a fourth embodiment of the invention. 1... Air introduction path, 2... Pressurized fan, 3... Gaseous impurity removal means, 4... Conveyance bell), 5.19.
27... Wafer 6... Drive roller, 7... Followed roller, 8... Wafer transport area, 9, 10, 11.2
9...Filter electrode, 12.31...DC power supply device, 13...Main body, 14...Temperature control tube, 15...
Heat medium, 16... Adsorbent, 17... Adsorbent, 18.
...Bake oven, 20...Heater, 21...Exhaust port,
22...Chamber, 23...Shutter, 24...
Exhaust port, 25°...High frequency power supply. 26... Electrode, 28 Figure 1 Figure 2 Figure 3 Figure 5 Figure 4 Figure 5 Figure 2 19: Wafer 23: Shutter

Claims (1)

[Claims] 1. A semiconductor manufacturing equipment that is in charge of one or more processes in the manufacturing process of a semiconductor device, and a gaseous impurity removal means that cleans the working atmosphere of the semiconductor manufacturing equipment. Semiconductor manufacturing equipment. 2. The semiconductor manufacturing apparatus according to claim 1, wherein the gaseous impurity removing means purifies the air supplied to the semiconductor manufacturing equipment. 3. The gaseous impurity removing means is configured by integrating an electrode into a filter medium, and is arranged between at least one first filter electrode arranged opposite to the air flow and adjacent to each of the filter electrodes. 3. The semiconductor according to claim 2, further comprising: a second filter electrode, and a power supply device that applies voltages of different polarities to the second filter electrode and the first filter electrode. Manufacturing equipment. 4. The semiconductor according to claim 2, wherein the gaseous impurity removing means comprises an adsorbent that adsorbs and traps gaseous substances in the air flow, and a temperature adjustment means that controls the temperature of the adsorbent. Manufacturing equipment. 5. The semiconductor manufacturing equipment is a sputtering device, and the gaseous impurity removing means is disposed near the object to be processed and is connected to a pair of electrodes to which a DC voltage is applied to adsorb ionized substances of atoms scattered by sputtering. The semiconductor manufacturing apparatus according to claim 2, characterized in that: