JPH09213679A - Vacuum device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the sensitivity of a particle sensor from being reduced by a method wherein an etching chamber is provided with an exhaust hole for particle measurement use and an exhaust tube and when etching gas is not made to flow through the tube, dusts are measured by the particle sensor in the exhaust tube. SOLUTION: A suction hole 13 is bored in the position, which opposes to a transfer chamber 6, on an etching chamber 1. Moreover, a particle sensor 16 is provided in an exhaust tube 14 connected between the hole 13 and an exhaust pump 11 via the third valve 15. Hereby, the sensor 16 can be prevented from being deteriorated due to a reactive product by shutting the third valve 15 at the generation of plasma. Moreover, etching gas sucked to the sensor 16 is made to desorb from the sensor 16 by winding a first heater 17 on the sensor 16, whereby the deterioration of the sensor 16 can be prevented from being produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum apparatus such as a dry etching apparatus, LV-CVD and plasma CVD apparatus for manufacturing a semiconductor device or the like.

[0002]

2. Description of the Related Art Dry etching is frequently used during the manufacturing process of semiconductor devices. Miniaturization of semiconductor devices,
As the degree of integration is improved, dust during processing in a vacuum device has a great influence on the product yield. In particular, vertical etching has been increasingly used in recent years in response to the miniaturization of the dimensions of semiconductor devices.

However, in vertical etching, the second
As shown in FIG.
2 means that there is no lateral etching, so 2
The traces of 2 are transferred, leaving the material to be etched, eg silicon oxide 23. For this reason, a pattern abnormality occurs, which is a cause of greatly reducing the manufacturing yield of semiconductor devices. Dust becomes a problem even in the submicron size.

A conventional dry etching apparatus for performing such dry etching has no means for quantitatively inspecting and monitoring dust inside the apparatus.
However, in order to solve the above problem, Japanese Patent Application Laid-Open No. 63-124526 discloses an apparatus for disposing a particle sensor in an exhaust pipe between an etching chamber and an exhaust pump as an example of a vacuum apparatus.

This device will be described with reference to FIG. In the figure, 31 is an etching chamber, 32 is a wafer mounting table disposed in the center of the etching chamber 31, 33 is a semiconductor wafer mounted on the wafer mounting table 32, and 34 is a semiconductor wafer 33 on the upper part of the etching chamber 31.
A grounded cathode in the shape of a plate which is approximately the same size and is arranged in parallel to each other, 35 is a high frequency power source connected to the wafer mounting table 32, and 36 is a semiconductor wafer 33 which is automatically supplied to the wafer mounting table 32, Store and etch chamber 31
A transfer chamber 37 is provided on the side surface at the height of the wafer mounting table 32. A gate valve 37 connects the etching chamber 31 and the transfer chamber 36 so that the semiconductor wafer 33 can be taken in and out and can be hermetically isolated.
Is an etching gas pipe for supplying an etching gas into the etching chamber 31, and 39 is an etching gas pipe 38.
The valve for supplying and stopping the etching gas arranged near the etching chamber 31 of the exhaust gas, the exhaust pipe 40 connected to the lower part of the etching chamber 31, and the exhaust pipe 41 connected to the tip of the exhaust pipe 40 for exhausting the etching chamber 31. Pump 42 is the exhaust pipe 4 near the etching chamber 31
Although not shown, laser light is radiated by a particle sensor arranged in the 0, and a scattering state of dust is measured by a photo sensor to measure the amount of dust.

[0006]

However, in the above apparatus, since the particle sensor 42 is always arranged in the exhaust pipe 40, the particle sensor 42 may be an etching gas or a reaction product due to the etching during the use of the etching gas. The solid reaction products that come into contact with each other and adhere to the laser light irradiation portion and the light receiving portion of the particle sensor remain attached. Therefore, there is a problem that the sensitivity of the particle sensor 42 decreases with the passage of time. Even when the reaction gas was not used, floating matter adhered during cleaning of the apparatus, etc., and there was a similar problem.

[0007]

SUMMARY OF THE INVENTION The present invention has been proposed to solve the above-mentioned problems, and includes a vacuum chamber, a gas pipe connected to the vacuum chamber via a first valve, and a first exhaust pipe connected to the vacuum chamber. In a vacuum device having an exhaust pump connected via a second valve and a second valve arranged in the first exhaust pipe, an intake hole formed in the vacuum chamber,
A vacuum device having a second exhaust pipe connecting an intake hole and an exhaust pump via a third valve and a particle sensor arranged between the third valve and the exhaust pump was configured to include reaction gas dust. If you want to measure dust in the state,
The measurement is performed by opening the valve and the third valve, and when measuring the dust excluding the reaction gas, the first valve is closed and the measurement is performed.
Even when the device is cleaned, the third valve is closed to prevent dust from adhering to prevent the sensitivity of the particle sensor from being lowered. Further, when the reaction gas flows in from the gas pipe, at least when the solid reaction product is scattered, the third valve is closed in the same manner to prevent the particle sensor from contacting the reaction product, thereby improving the sensitivity of the particle sensor. Prevent decline.

Further, the vacuum device has a transfer chamber connected to the vacuum chamber via a fourth valve, and the intake port constitutes a vacuum device arranged at a position facing the transfer chamber, and the gate valve is opened. Occasionally, a gas flow is generated from the transfer chamber in the direction of the particle sensor to increase the dust measurement sensitivity.

Further, the first for heating the particle sensor
The heating means and / or the second valve between the third valve and the intake hole
A vacuum device having a second heating means for heating the exhaust pipe is configured, and the heating means provided with a particle sensor constantly heats the inflowing etching gas and adsorbed substances of reactive organisms to generate particles. Prevent the sensor sensitivity from decreasing. Further, by constantly heating with the heating means provided with the second exhaust pipe, it is possible to prevent the reaction product from being scattered after being deposited on the second exhaust pipe and becoming measurement noise of the particle sensor.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIG. 1 by taking a dry etching apparatus as an example. Only the main part is shown, and parts not related to the explanation are omitted.

In the drawing, 1 is an etching chamber and 2 is
Is a wafer mounting table arranged in the center of the etching chamber 1, 3 is a semiconductor wafer mounted on the wafer mounting table 2, and 4 is an upper surface of the etching chamber 1 which faces the semiconductor wafer 3 in substantially the same size in parallel. A grounded cathode 5 in the form of a flat plate, 5 is a high-frequency power source connected to the wafer mounting table 2, 6 is a semiconductor wafer 3 which is automatically supplied to and housed in the wafer mounting table 2, and the wafer is placed on the side surface of the etching chamber 1. A transfer chamber arranged at the height of the mounting table 2, a gate valve 7 which is a fourth valve which connects the etching chamber 1 and the transfer chamber 6 in a state where the semiconductor wafer 3 can be taken in and out, and which can be hermetically isolated from each other, 8 Is an etching gas pipe for supplying an etching gas into the etching chamber 1, and 9 is an etching gas pipe 8 near the etching chamber 1. A first valve for supplying and stopping the provided etching gas, 10 is a first exhaust pipe connected below the etching chamber 1, and 11 is an exhaust connected to the tip of a first exhaust pipe 10 for exhausting the etching chamber 1. A pump, 12 is the etching chamber 1 of the first exhaust pipe 10.
It is a second valve arranged in the vicinity.

The features of the present invention thereafter are as follows: 13 is an intake hole formed in the etching chamber 1 at a position facing the gate valve 7, and 14 is the first exhaust pipe 10 between the second valve 12 and the exhaust pump 11 and the intake port. Second exhaust pipe connected to hole 13, 15
Is a third valve disposed near the intake hole 13 of the second exhaust pipe,
Reference numeral 16 is a particle sensor arranged between the third valve 15 and the first exhaust pipe, 17 is a first heater which is a heating means wound around the particle sensor 16, and 18 is an intake hole 13 from the intake hole 13 to the third valve. A second heater, which is a heating means wound around the second exhaust pipe 14 in the vicinity, is a fifth valve 19 disposed between the exhaust pump 11 and the particle sensor 16.

The method of using this device will be described below. First valve 9 and gate valve 7 of etching gas pipe 8
The second valve 12, the third valve 15, and the fifth valve
The exhaust pump 11 is operated with the valve 19 opened to exhaust the inside of the etching chamber 1 to a vacuum degree of about 10 −6 Torr. Next, the second valve 12, the fifth valve 1
9 is closed, and nitrogen is introduced through a nitrogen pipe (not shown).
Subsequently, the second valve 12 and the fifth valve 19 are opened again, and the inside of the etching chamber 1 is evacuated to about 10 −6 Torr.
The degree of vacuum is r.

At this time, in the transfer chamber 6, a semiconductor wafer 3 in which a region not etched with aluminum is covered with a photoresist is held in a carrier (not shown) in a state of being horizontally separated one by one. -2
The vacuum state of Torr is kept. Although not shown, exhaust means for exhausting only the inside of the transfer chamber 6 is connected. Subsequently, the gate valve 7 is opened, and at the same time, the third valve 15 located at the opposite position is also opened. At this time, due to the pressure difference between the transfer chamber 6 and the etching chamber 1, the atmospheric gas in the transfer chamber 6 is introduced into the second exhaust pipe 14 from the intake holes 13 together with the etching gas, and the dust is measured by the particle sensor 16 ( (The measurement system is not shown). Subsequently, one semiconductor wafer 3 is automatically mounted on the wafer mounting table 2 from the inside of the transfer chamber 6.

Subsequently, the first valve 9 is opened with the exhaust pump 11 in operation, and an etching gas such as a mixed gas of boron trichloride gas and chlorine gas is mixed from the etching gas pipe 8 at a constant ratio. Pour into the chamber and adjust the vacuum to 10 -3 Torr. At this time, the measurement is performed including the dust in the transfer chamber 6 and the dust of the etching gas. At the time of this measurement, the second valve 12 may be closed and all the exhaust may be performed through the second exhaust pipe 14 to bring a large amount of gas into contact with the particle sensor 16 to improve the measurement accuracy. At this time, in order to prevent the reaction gas from adsorbing, the first heater 17 is energized and heated. Also, in order to prevent the aluminum trichloride generated by the ion etching from cooling and evaporating by heating the precipitated crystals, the second heater is used in order to prevent the dust measurement value from becoming abnormal due to rising dust during the next dust measurement. 18
Energize and heat. The first heater 17 is the second at about 80 ° C.
The heater 18 is controlled at about 100 ° C.

Next, the third valve 15 and the fifth valve 1
9 and gate valve 7 are closed. Subsequently, a high-frequency voltage is applied between the grounded cathode and the wafer mounting table 2 to generate plasma, and aluminum in a region not covered with the photoresist is etched and removed. Then,
When the dry etching is completed, the power supply from the high frequency power supply 5 is stopped, the first valve 9 is closed, and the supply of the etching gas is stopped.

Although the semiconductor wafer 3 is arranged below the cathode 4 in the present description, it may be arranged in parallel with each other.

Subsequently, the gate valve 7 is opened and the semiconductor wafer 3 is placed on the carrier in the transfer chamber 6. Next, the semiconductor wafer 3 is the gate valve 7
After passing through, the gate valve 7 is closed.

The above operation is repeated to perform dry etching one by one. When the dry etching of all the semiconductor wafers 3 is completed, the energization of the first heater 17 and the second heater 18 is stopped.

In this way, the intake hole 13 is formed at a position facing the transfer chamber 6 of the etching chamber 1, and the second hole is connected between the intake hole 13 and the exhaust pump 11.
Since the particle sensor 16 is disposed in the exhaust pipe 14 via the third valve 15, the particle sensor 16 can be prevented from being deteriorated by a reactive organism by closing the third valve 15 when plasma is generated. In addition, by desorbing the etching gas adsorbed by winding the first heater 17 around the particle sensor 16, deterioration of the particle sensor 16 can be prevented.

The structure of the particle sensor of the present invention can be applied not only to the dry etching apparatus but also to plasma CVD, low pressure CVD, etc. as long as it is an apparatus for producing reaction products. Further, although no reactive organism is generated, it can be applied to dust measurement of a sputtering device.

According to the present invention, the amount of dust in the dry etching apparatus can be constantly monitored for each sheet.
Therefore, when the amount of dust in the dry etching device reaches a certain value or more, the dry etching device can be immediately disassembled and cleaned. As a result, dry etching is not continued even if the amount of dust generated exceeds a specified value, and the production yield of semiconductor devices can be prevented from decreasing. In addition, as in the case where the number of processed sheets determines the cleaning inside the device, cleaning is not performed even if the amount of dust does not increase, and the amount of dust remains even if the date and time has passed since the previous cleaning. There is no need to disassemble and clean it below a certain value. Therefore, the operating rate of the dry etching apparatus is improved.

[0023]

EFFECTS OF THE INVENTION By providing an exhaust hole and an exhaust pipe for particle measurement in an etching chamber, dust is measured by a particle sensor in the exhaust pipe when an etching gas is not flown, and a particle sensor is etched by a valve when an etching gas is flown. Since the contact with the gas is blocked, it is possible to prevent the sensitivity of the particle sensor from decreasing. Further, by providing an exhaust hole at a position facing the transformer chamber and directing a flow of air due to a pressure difference when the wafer is inserted from the transformer chamber toward the exhaust hole, dust on the wafer can be measured with high sensitivity. Further, the particle sensor may be provided with a heating means to prevent adsorption of etching gas and prevent deterioration of sensitivity.

[Brief description of drawings]

FIG. 1 is a block diagram of an ion etching apparatus of the present invention.

FIG. 2 is a sectional view of a semiconductor wafer with abnormal etching.

FIG. 3 Block diagram of the proposed ion etching device

[Explanation of symbols]

 1 Vacuum Chamber (Etching Chamber) 8 Gas Pipe (Etching Gas Pipe) 9 First Valve 10 First Exhaust Pipe 11 Exhaust Pump 12 Second Valve 13 Intake Hole 14 Second Exhaust Pipe 15 Third Valve 16 Particle Sensor

Claims (3)

[Claims] 1. A vacuum apparatus comprising a vacuum chamber, a gas pipe connected to the vacuum chamber via a first valve, and an exhaust pump connected to the vacuum chamber via a second valve by a first exhaust pipe, wherein the vacuum is provided. It has an intake hole formed in the chamber, a second exhaust pipe connecting the intake hole and the exhaust pump via a third valve, and a particle sensor arranged between the third valve and the exhaust pump. A vacuum device characterized in that 2. The vacuum apparatus has a transfer chamber connected to the vacuum chamber via a fourth valve,
The vacuum apparatus according to claim 1, wherein the air intake hole is provided at a position facing the transfer chamber. 3. A first heating means for heating the particle sensor and / or a second heating means for heating the second exhaust pipe between the third valve and the intake hole are provided. The vacuum device according to claim 1 or 2.