JP2005209754A - Substrate-treating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the etching of a protecting tube in gas cleaning, or that of the wiring of a thermocouple in wet cleaning, even if the protecting tube for protecting the thermocouple is installed in a treatment chamber. <P>SOLUTION: A substrate-treating device comprises a treatment chamber for treating a substrate, a temperature detecting means 263 provided in the treatment chamber, a first protecting tube 10 for covering the temperature detecting means, and a second protecting tube 20 for covering the first protecting tube. Thus, even if film-formation treatment is made in the treatment chamber, a by-product adheres to only the second protecting tube since the first protecting tube for protecting the thermocouple is protected by the second protecting tube. In this manner, only the second protecting tube in which the by-product adheres to may be washed in wet cleaning, thus dispensing with the cleaning of the first protecting tube having thermocouple wiring, and hence preventing a cleaning liquid from adhering to the thermocouple wiring. And etching gas comes into contact with only the second protecting tube in gas cleaning, thus preventing the first protecting tube for protecting the thermocouple from being corroded by the etching gas and a hole from being opened, and preventing the thermocouple from being damaged. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a semiconductor manufacturing technique, and more particularly, to a heat treatment technique in which a substrate to be processed is accommodated in a processing chamber and processed while being heated by a heater. For example, oxidation processing and diffusion are performed on a semiconductor wafer on which a semiconductor integrated circuit device is fabricated. The present invention relates to a substrate processing apparatus which is effective for use in a substrate processing apparatus used for processing, reflow for carrier activation after ion implantation, planarization, annealing, and thermal CVD reaction.

An example of a processing chamber structure of a substrate processing apparatus, for example, a semiconductor manufacturing apparatus is shown in FIG. FIG. 3 shows a longitudinal sectional structure of the processing chamber. FIG. 4 is a diagram showing a conventional temperature detecting means.

As shown in FIG. 3, a processing chamber 201 is formed by a cylindrical reaction tube 205 made of, for example, quartz having an upper end closed and an opening at the lower end, a seal cap 219 covering the lower end opening of the reaction tube 205, and the like. The A substrate 200 such as a wafer is placed in the processing chamber 201, the substrate 200 is brought to a desired temperature by a heater 207 that heats the substrate, and then the gas supply pipe 23.
By supplying the processing gas from 2 into the processing chamber 201, a desired processing is performed on the substrate 200.

In addition, a thermocouple 263 is provided in the processing chamber 201 as a temperature detecting unit for measuring the temperature in the processing chamber 201 and controlling the output of the heater 207. As shown in FIG. 4, the thermocouple 263 is provided in the processing chamber 201 in a state of being inserted into a protective tube 50 made of quartz or the like in order to prevent corrosion due to the processing gas. In order to more accurately measure the temperature of the substrate 200 and appropriately control the output of the heater 207, the thermocouple 263 is provided in the processing chamber 201 so as to measure the temperature near the substrate 200 as much as possible. Has been.

Among the above-described substrate processes, there is one that forms a thin film on the substrate 200 (film formation process).
. When film formation is performed in the processing chamber 201, the thin film is not only on the substrate 200 but also on the inner wall of the processing chamber 201 and the surface of the protective tube 50 (that is, where the processing gas contacts). A film is formed as a product. Since these by-products easily peel off as the film thickness increases and cause particles, they must be removed (cleaned) regularly.

As the cleaning method, a cleaning gas (etching gas) is supplied into the processing chamber 201 to etch (shave off) by-products attached in the processing chamber 201.
There is a gas cleaning to remove. As another cleaning method, there is wet cleaning in which a part (such as the reaction tube 205 or the protective tube 50) to which a by-product is attached is removed from the substrate processing apparatus and the by-product is removed using a cleaning liquid.

However, as described above, gas cleaning is a method of etching and removing by-products, so that not only by-products but also the reaction tube 205 and the protective tube 50 are etched, and a predetermined strength is obtained. Or in the protective tube 50,
A hole may be opened by etching, and the thermocouple 263 may be damaged.

In the wet cleaning, when the protective tube 50 is cleaned, the wiring 30 of the thermocouple 263 extending from the protective tube 50 is protected so as not to touch the cleaning liquid. May get wet with the cleaning solution. Thermocouple 263
If the wiring 30 comes into contact with the cleaning liquid, it will be etched, causing a problem that the temperature cannot be measured.

Therefore, the object of the present invention is to prevent etching of the protective tube during gas cleaning and etching of the thermocouple wiring during wet cleaning even when a protective tube for protecting the thermocouple is installed in the processing chamber. can do.

In order to solve the above problems, the present invention is configured as described in the claims. That is, the present invention provides a processing chamber for processing a substrate, temperature detection means provided in the processing chamber, a first protective tube covering the temperature detection means, and the first The substrate processing apparatus includes a second protective tube that covers the protective tube.

According to the present invention, a processing chamber for processing a substrate, temperature detection means provided in the processing chamber, a first protection tube covering the temperature detection means, and a second protection covering the first protection tube Since the first protective tube for protecting the thermocouple is protected by the second protective tube even if the film forming process is performed in the processing chamber, the by-product Adheres only to the second protective tube. Thus, during wet cleaning, it is only necessary to clean the second protective tube to which the by-product is attached. Therefore, it is not necessary to clean the first protective tube having the thermocouple wiring. The cleaning liquid does not adhere to the pair of wires. Further, since the etching gas contacts only the second protective tube during gas cleaning, the first protective tube protecting the thermocouple is corroded by the etching gas and a hole is opened to damage the thermocouple. There is nothing.

An outline of a semiconductor manufacturing apparatus which is an example of a substrate processing apparatus to which the present invention is applied will be described with reference to FIG.

A cassette stage 105 is provided on the front side of the inside of the housing 101 as a holding member transfer member that transfers the cassette 100 as a substrate storage container to and from an external transfer device (not shown). Is provided with a cassette elevator 115 as an elevating means, and a cassette transfer machine 114 as a conveying means is attached to the cassette elevator 115. On the rear side of the cassette elevator 115, a cassette shelf 109 is provided as a mounting means for the cassette 100, and the cassette shelf 109 is arranged on the slide stage 12.
2 is provided so that it can traverse. A buffer cassette shelf 110 is provided above the cassette shelf as means for placing the cassette 100. Further, a clean unit 118 is provided on the rear side of the buffer cassette shelf 110, and clean air is supplied to the housing 1
It is comprised so that the inside of 01 may be distribute | circulated.

A processing furnace 202 is provided above the rear portion of the casing 101, and below the processing furnace 202,
The load lock chamber 102 as a semi-cylindrical airtight chamber is a gate valve 244 as a gate valve.
A load lock door 123 as a partitioning means is provided on the front surface of the load lock chamber 102 at a position facing the cassette shelf 109. The load lock chamber 1
In the boat 02, a boat elevator 1 as an elevating means for elevating and lowering a boat 217 as a substrate holding means for holding wafers 200 as substrates in a multi-stage in a horizontal posture to the processing furnace 202.
21 is installed, and a seal cap 219 as a lid is attached to the boat elevator 121 to support the boat 217 vertically. Between the load lock chamber 102 and the cassette shelf 109, a transfer elevator (not shown) as an elevating means is provided, and a wafer transfer machine 112 as a transfer means is attached to the transfer elevator.

Hereinafter, a series of operations in the substrate processing apparatus will be described. The cassette 100 transported from an external transport device (not shown) is placed on the cassette stage 105, and the orientation of the cassette 100 is converted by 90 ° on the cassette stage 105. Further, the cassette elevator 115 is moved up and down, and traversed. The cassette is transferred to the cassette shelf 109 or the buffer cassette shelf 110 by the cooperation of the operation and the advance / retreat operation of the cassette transfer device 114.

The wafer transfer device 112 transfers the wafer 200 from the cassette shelf 109 to the boat 217. In preparation for transferring the wafer 200, the boat 217 is lowered by the boat elevator 121, and the processing furnace 2 is moved by the gate valve 244.
02 is closed, and purge gas such as nitrogen gas is introduced into the load lock chamber 102 from the purge nozzle 234. After the load lock chamber 102 is restored to atmospheric pressure, the load lock door 123 is opened.

The horizontal slide mechanism 122 horizontally moves the cassette shelf 109 and positions the cassette 100 to be transferred so as to face the wafer transfer machine 112. The wafer transfer machine transfers the wafers 200 from the cassette 100 to the boat 217 by cooperation of lifting and rotating operations. The transfer of the wafer 200 may involve several cassettes 10.
After the transfer of a predetermined number of wafers to the boat 217 is completed, the load lock door 123 is closed and the load lock chamber 102 is evacuated.

After the evacuation is completed, when the gas is introduced from the gas purge nozzle 234 and the inside of the load lock chamber 102 is returned to the atmospheric pressure, the gate valve 244 is opened, and the boat elevator 121 causes the boat 217 to move to the processing furnace. 202, the gate valve 244 is closed. The boat 217 may be charged into the processing furnace 202 in a state of less than atmospheric pressure without returning the pressure inside the load lock 102 to atmospheric pressure after completion of evacuation.
After predetermined processing is performed on the wafer 200 in the processing furnace 202, the gate valve 2
44 is opened, the boat 217 is pulled out by the boat elevator 121, and
After the inside of the load lock chamber 102 is restored to atmospheric pressure, the load lock door 123 is opened.

The processed wafer 200 is transferred from the boat 217 to the cassette stage 105 through the cassette shelf 109 by the reverse procedure of the above-described operation, and unloaded by an external transfer device (not shown).

  The transport operation of the cassette transfer machine 114 and the like is controlled by the transport control means 124.

Next, as an example of processing performed in a processing furnace of a substrate processing apparatus to which the present invention is applied, a film forming process on a substrate such as a wafer using the low pressure CVD processing furnace shown in FIG. 3 will be briefly described. To do.
A reaction tube (also referred to as an outer tube) 205 is made of a heat-resistant material such as quartz (SiO 2), and has a cylindrical shape with an upper end closed and an opening at the lower end. The inner tube (hereinafter referred to as the inner tube 204) has a cylindrical shape having openings at both ends of the upper end and the lower end, and is disposed concentrically within the outer tube 205. A space between the outer tube 205 and the inner tube 204 forms a cylindrical space 250. The gas rising from the upper opening of the inner tube 204 passes through the cylindrical space 250 and is exhausted from the exhaust pipe 231.

A manifold 209 made of, for example, stainless steel is engaged with lower ends of the outer tube 205 and the inner tube 204, and the outer tube 2 is connected to the manifold 209.
05 and the inner tube 204 are held. The manifold 209 is fixed to holding means (hereinafter referred to as a heater base 251). An annular flange is provided at each of the lower end portion of the outer tube 205 and the upper opening end portion of the manifold 209, and an airtight member (hereinafter referred to as an O-ring 220) is disposed between the flanges. Has been.

A disc-shaped lid (hereinafter referred to as a seal cap 219) made of, for example, stainless steel is detachably attached to the lower end opening of the manifold 209 through an O-ring 220 so as to be hermetically sealed. A gas supply pipe 232 is provided in the seal cap 219 so as to penetrate therethrough. A processing gas is supplied into the outer tube 205 through these gas supply pipes 232. These gas supply pipes 232 are connected to a gas flow rate control means (hereinafter referred to as a mass flow controller (MFC) 241). The MFC 241 is connected to a gas flow rate control unit, and the flow rate of the supplied gas is set to a predetermined amount. It can be controlled.

Connected to the upper portion of the manifold 209 are a pressure regulator (for example, an APC and N2 ballast controller, hereinafter referred to as APC 242) and a gas exhaust pipe 231 connected to an exhaust device (hereinafter referred to as a vacuum pump 246). The gas flowing in the cylindrical space 250 between the outer tube 205 and the inner tube 204 is discharged, and the inside of the outer tube 205 is AP
By controlling the pressure with C242, the pressure is detected by pressure detection means (hereinafter referred to as pressure sensor 245) so as to obtain a reduced pressure atmosphere of a predetermined pressure, and is controlled by the pressure controller.

The seal cap 219 is connected to a rotating means (hereinafter referred to as a rotating shaft 254).
54, the substrate holding means (hereinafter referred to as boat 217) and the substrate (hereinafter referred to as wafer 200) held on the boat 217 are rotated. The seal cap 219 is connected to lifting means (hereinafter referred to as a boat elevator 115) and lifts the boat 217. The drive control unit controls the rotating shaft 254 and the boat elevator 115 to have predetermined speeds.

On the outer periphery of the outer tube 205, heating means (hereinafter referred to as a heater 207) is concentrically arranged. The heater 207 detects the temperature by temperature detection means (hereinafter, thermocouple 263) so that the temperature in the outer tube 205 becomes a predetermined processing temperature, and controls it by the temperature control unit.

An example of the low pressure CVD processing method using the processing furnace shown in FIG. 3 will be described. First, the boat 217 is lowered by the boat elevator 115. A plurality of wafers 200 are held on the boat 217. Next, the temperature in the outer tube 205 is set to a predetermined processing temperature while being heated by the heater 207. The inside of the outer tube 205 is filled with an inert gas in advance by the MFC 241 connected to the gas supply pipe 232, and the boat 217 is lifted and moved into the outer tube 205 by the boat elevator 115, and the internal temperature of the outer tube 205 is increased. Is maintained at a predetermined processing temperature. After the inside of the outer tube 205 is exhausted to a predetermined vacuum state, the boat 217 and the wafer 200 held on the boat 217 are rotated by the rotating shaft 254. At the same time, a processing gas is supplied from a gas supply pipe 232. The supplied gas rises in the outer tube 205 and is evenly supplied to the wafer 200.

The inside of the outer tube 205 during the low pressure CVD process is exhausted through the exhaust pipe 231, and the pressure is controlled by the APC 242 so as to be a predetermined vacuum, and the low pressure CVD process is performed for a predetermined time.

When the reduced-pressure CVD process is completed in this way, the gas in the outer tube 205 is replaced with an inert gas and the pressure is set to normal pressure, and then the boat elevator 115 is used to proceed to the reduced-pressure CVD process for the next wafer 200. The boat 217 is lowered and the boat 217 and the processed wafer 200 are taken out from the outer tube 205. Outer tube 205
The processed wafer 200 on the boat 217 taken out from the wafer is replaced with an unprocessed wafer 200 and is again raised into the outer tube 205 in the same manner as described above, and a low pressure CVD process is performed.

Note that, up to one example, the processing conditions processed in the processing furnace of the present embodiment are as follows: in the formation of the SiN film, the wafer temperature is about 740 ° C., the gas type and the gas supply amount are NH4 0.5 SLM, DCS (dichlorosilane ) Is 0.2 SLM, and the processing pressure is about 120 Pa.

Next, the temperature detection means (thermocouple 263) in the present invention will be described with reference to FIG.
As described above, in the processing chamber 201, the thermocouple 263 is provided as a temperature detecting means for measuring the temperature in the processing chamber 201 and controlling the output of the heater 207. Further, the thermocouple 263 is provided in the processing chamber 201 to measure the temperature of the substrate more accurately and appropriately control the output of the heater 207, and measures the temperature near the substrate 200 as much as possible. Has been.

The thermocouple 263 is, for example, a first made of quartz in order to prevent corrosion due to the processing gas.
The protective tube 10 is protected, and a wiring 30 connected to the thermocouple 263 extends from one end of the first protective tube. A second protective tube 20 made of, for example, quartz is provided so as to cover the outer wall of the first protective tube 10. A processing gas (film forming gas or etching gas) is passed through the opening 5 of the second protective tube 20 in the gap 15 between the first protective tube 10 and the second protective tube 20. The opening 5 is sealed with a sealing member 40 so as not to enter. The sealing member 40 is made of, for example, quartz and SiC, and has a tapered shape as shown in FIG. 1B or a pluggable shape as shown in FIG.
0 is provided in the opening 5 so that it can be inserted and discharged.

The substrate processing apparatus to which the present invention is applied protects the thermocouple 263 with the first protective tube 10, and further covers the first protective tube 10 with the second protective tube 20. Since the gap 15 between the protective tube 10 and the second protective tube 20 is sealed by the sealing member 5, it is possible to prevent the processing gas from entering the gap 15 and the first protective tube. No by-product is attached to 10. Therefore, it is not necessary to clean the first protective tube 10.

Since the sealing member 40 is provided so that it can be attached and detached from the opening 5 in a substantially airtight manner, during the wet cleaning, the sealing member 40 is detached from the opening 5 and the second protective tube 20 is removed. It is only necessary to separate the first protective tube 10 and wet-clean only the second protective tube 20. Therefore, the wiring 30 of the thermocouple 263 extending from the first protective tube 10 contacts the cleaning liquid. There is no. Further, as in the prior art, it is not necessary to clean while protecting the wiring 30 of the thermocouple 263 at the time of wet cleaning, so that maintainability is facilitated.

Further, during the gas cleaning, the etching gas acts on the second protective tube 20 and the reaction tube 205 to which the by-products are attached. Therefore, as in the conventional case, the protection for protecting the thermocouple 263 with the etching gas is performed. There is no possibility that the tube 50 (corresponding to the first protective tube 10 in this embodiment) has a hole, which damages the thermocouple 263 and shortens the life of the thermocouple 263. If the second protective tube 20 is etched and the predetermined strength cannot be maintained, only the second protective tube 20 may be replaced with a new one, and the first thermocouple 263 is enclosed. Compared with the case where the protective tube 10 is replaced, the maintenance cost of the substrate processing apparatus can be reduced.

Schematic diagram of thermocouple to which the present invention is applied Schematic showing a substrate processing apparatus of the present invention Schematic (longitudinal sectional view) of the processing furnace of the substrate processing apparatus in the present invention Schematic diagram of conventional thermocouple

Explanation of symbols

5 opening 10 first protective tube 15 clearance 20 second protective tube 30 wiring 40 sealing member 50 protective tube 109 cassette shelf 110 buffer cassette shelf 112 wafer transfer device 114 cassette transfer device 121 boat elevator 122 slide stage 123 load Lock door 124 Transfer control means 200 Wafer 201 Processing chamber 202 Processing furnace 205 Reaction tube (outer tube)
217 Boat 219 Seal cap 244 Gate valve 263 Thermocouple 232 Gas supply pipe

Claims (1)

A processing chamber for processing the substrate;
Temperature detection means provided in the processing chamber;
A first protective tube covering the temperature detecting means;
A substrate processing apparatus comprising: a second protective tube that covers the first protective tube.

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