JP3137773B2 - Method for manufacturing semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for manufacturing a semiconductor device including a CVD device in a semiconductor manufacturing facility.
Especially in the supply of dopants for semiconductor wafers, C
The present invention relates to a method for manufacturing a semiconductor device capable of making the concentration of a dopant in a VD film uniform, and a technique effective when applied to a CVD apparatus.

[0002]

2. Description of the Related Art For example, in a low-pressure CVD apparatus in a semiconductor manufacturing facility, a process gas is supplied into a reaction chamber while being sucked by a vacuum pump to reduce the pressure in the reaction chamber to a pressure lower than atmospheric pressure (0.1 to 1.1. 0 Torr) while CV
D film is generated, and is mainly used for forming a polysilicon film and a silicon nitride film.

[0003] In this CVD apparatus, a dopant 2 and a process gas 3 made of an element constituting a thin film material are similarly placed in a cylindrical inner tube 1 as shown in FIG. In other words, the gas is supplied into the reaction chamber from the inlet / outlet of the semiconductor wafer toward the gas exhaust direction.

[0004]

However, in the above prior art, no consideration is given to the case where the activation energy of the dopant is significantly different from the activation energy of the process gas. Is a problem in generating

[0005] That is, the energy difference between the dopant and the process gas greatly affects the dopant concentration in the film. When this energy difference is large, the dopant concentration changes depending on the position in the reaction chamber, and the dopant concentration changes. There is a problem that uniformity cannot be obtained.

Further, since the distance from the supply port of the dopant to each semiconductor wafer is different, the concentration of the dopant in the film varies depending on the position in the reaction chamber. There is a problem that a CVD film having a uniform dopant concentration cannot be formed.

Accordingly, an object of the present invention is to reduce the difference in activation energy by preheating the dopant and to keep the distance from the supply port of the dopant to each semiconductor wafer equal to achieve a uniform dopant concentration. An object of the present invention is to provide a method of manufacturing a semiconductor device and a CVD apparatus capable of improving the performance.

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

[0009]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, in the method of manufacturing a semiconductor device according to the present invention, a first tube (an inner tube) and a second tube provided inside the first tube and having a plurality of openings (a tube of a pre-heating chamber for a dopant) are provided. And a device provided with a reaction chamber having a wafer processing area for processing a plurality of semiconductor wafers provided therein, and a first gas is supplied from one end inside the tube of the dopant preheating chamber to the wafer processing area. (Process gas), and a second gas is supplied between the inner tube and the tube of the dopant preheating chamber, that is, into the dopant preheating chamber.
Gas (dopant) is supplied, the dope is supplied to the wafer processing region from the plurality of holes, and the process gas and the doping agent are reacted, and a film doped with the dopant component is set in the wafer processing region. And a step of forming it on a semiconductor wafer. In this case, the process gas is a gas containing silicon or the like, the doped film is a polysilicon film or the like, and the dopant is preheated in a dopant preheating chamber.

In another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, wherein the device is formed in the dopant preheating chamber,
A process gas having a controlled flow rate is supplied to the wafer processing region from one inner side of the tube of the dopant preheating chamber having a plurality of partitioned regions, and the flow rate is controlled to each of the plurality of partitioned regions. A controlled doping agent is supplied, and a doping agent is supplied to the wafer processing region from a plurality of openings, and the process gas and the doping agent are reacted to form a film on the semiconductor wafer installed in the wafer processing region. It has a process of performing.

Further, the CVD apparatus of the present invention comprises: an inner tube; a pre-heating chamber for a dopant provided in the inner tube; a wafer processing area provided inside the pre-heating chamber for the dopant; A gas inlet for introducing a process gas from one end of the processing region, a gas inlet for introducing a dopant into the dopant preheating chamber, and a dopant provided in the dopant preheating chamber, supplying the dopant to the wafer processing region. And a plurality of openings for making the holes. Further, another CVD apparatus of the present invention is such that a doping agent preheating chamber is formed in a plurality of divided regions, and gas introduction means for controlling a flow rate of a process gas and introducing the process gas from one end side of the wafer processing region, Gas introduction means for controlling the flow rate and introducing the dopant into each of the plurality of divided regions,
And a plurality of apertures provided in each of the plurality of partitioned regions for supplying a dopant to the wafer processing region.

[0013]

According to the method of manufacturing a semiconductor device and the CVD apparatus described above, the difference in activation energy from the process gas can be reduced by providing the dopant preheating chamber in the inner tube. That is, since the doping agent is heated before flowing into the reaction chamber, the doping agent reacts immediately after flowing into the reaction chamber and is taken into the film.

In this case, since the dopant is supplied in a shower form from the periphery of the semiconductor wafer, the distance from the supply port of the dopant to each semiconductor wafer is kept equal,
Variation in the concentration of the dopant in the film depending on the position in the reaction chamber can be reduced. That is, the dopant is uniformly fed into the reaction chamber and spreads uniformly in the reaction chamber, so that the film of each semiconductor wafer is uniformly doped.

Further, by controlling the flow rate of the dopant in each of the plurality of divided dopant preheating chambers,
By controlling the concentration of the dopant, the uniformity of the dopant concentration can be further improved.

[0016] This makes it possible to form a CVD film having a uniform dopant concentration on each of a plurality of semiconductor wafers in a batch process in a reaction chamber.

[0017]

Embodiment 1 FIG. 1 is a configuration diagram showing a CVD apparatus according to one embodiment of the present invention, and FIG. 2 is a schematic configuration diagram showing a reaction chamber used in the CVD apparatus of this embodiment.

First, the configuration of the CVD apparatus of this embodiment will be described with reference to FIG.

The CVD apparatus of this embodiment is, for example, a low-pressure CVD apparatus for forming a polysilicon film on a semiconductor wafer, and has a reaction chamber 11 made of cylindrical quartz or the like which is cut off from the outside air. A gas supply control unit 12 for controlling the supply of a predetermined dopant and a process gas comprising elements constituting the thin film material, and a wafer heating unit 1 for heating a semiconductor wafer in the reaction chamber 11 by a resistance heater or the like.
3 and a vacuum exhaust unit 14 for reducing the pressure in the reaction chamber 11 by a mechanical booster pump or the like.

The inner tube 15 of the reaction chamber 11
2, a dopant preheating chamber 16 for heating the dopant to a predetermined temperature is provided, and the dopant 17 introduced from the supply port is heated to a predetermined temperature through the dopant preheating chamber 16. It is heated so that the activation energy difference from the process gas 18 is reduced.

Further, a plurality of openings 19 are formed in the dopant preheating chamber 16. When the dopant 17 is supplied through these openings 19, a semiconductor wafer (not shown) is supplied through the dopant preheating chamber 16. Is supplied in a shower form from the peripheral portion of the container.

The dopant preheating chamber 16 in the inner tube 15 can be easily manufactured by inserting a cylindrical quartz tube having a shower-like hole into the inner tube 15 and welding both ends.

Next, the operation of this embodiment will be described.

The CVD apparatus configured as described above supplies the process gas 18 into the reaction chamber 11 and sucks it from one of them, and depressurizes the reaction chamber 11 to a pressure lower than atmospheric pressure (0.1 to 0.1). (1.0 Torr) while the CVD film is formed.

For example, in forming a polysilicon film, a monosilane gas (Si
H ₄ ) is used, and phosphorus (P) is supplied as the dopant 17. Then, at a generation temperature of about 600 ° C., a polysilicon film (P-do
ped-poly Si film) is generated.

In this case, the doping agent 17 is introduced into the doping preheating chamber 16, and the doping agent 17 is heated to a temperature at which the activation energy is substantially equal to that of the process gas 18.

Then, the dopant 17 is supplied in a shower form from the plurality of openings 19 of the dopant preheating chamber 16 and is uniformly fed into the reaction chamber 11, so that the dopant 17 spreads uniformly in the reaction chamber 11. Then, the dopant 17 reacts more quickly, is taken into the film, and can uniformly dope the dopant 17 to a plurality of semiconductor wafers (not shown) by batch processing.

Therefore, according to the CVD apparatus of this embodiment,
By providing the dopant preheating chamber 16 in the inner tube 15 of the reaction chamber 11, the difference in the activation energy of the dopant 17 with the process gas 18 which has been a problem in the past is reduced, and the dopant 17 is quickly removed. Can be taken into the film by the reaction, and the dopant concentration can be made uniform for a plurality of semiconductor wafers.

In addition, by forming a plurality of openings 19 in the dopant preheating chamber 16, the dopant 17 can be supplied in a shower form from the periphery of the semiconductor wafer. It is possible to reduce the variation in the concentration of the dopant 17 in the film depending on the position inside.

[0030]

Embodiment 2 FIG. 3 is a schematic diagram showing a reaction chamber used in a CVD apparatus according to another embodiment of the present invention.

The CVD apparatus according to the present embodiment employs a low pressure CV for forming a polysilicon film on a semiconductor wafer as in the first embodiment.
As shown in FIG. 3, a plurality of openings 19 are formed in the inner tube 15 of the reaction chamber 11, and a dope preheating chamber 16 for heating the dope 17 to a predetermined temperature.
a, which is different from the first embodiment in that the structure of the dopant preheating chamber 16a is different.

That is, the dopant preheating chamber 16a of this embodiment is divided into a plurality of independently controllable chambers.
A mass flow controller (MFC) 20 is connected to each of the divided dopant preheating chambers 16a,
The doping agent 17 is controlled by the mass flow controller 20.
Is controlled.

Therefore, according to the CVD apparatus of this embodiment,
Since the mass flow controller 20 is connected to each of the divided dopant preheating chambers 16a, the flow rate of the dopant 17 can be controlled in each of the dopant preheating chambers 16a. Further, the uniformity of the dopant concentration can be further improved.

As described above, the invention made by the inventor has been specifically described based on the first and second embodiments. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the invention. It goes without saying that it is possible.

For example, in the CVD apparatus of the present embodiment, a low pressure C for forming a polysilicon film on a semiconductor wafer is used.
Although the case of the VD apparatus has been described, the present invention is not limited to the above-described embodiment, and the silicon oxide film (S
The present invention can be widely applied to CVD apparatuses for forming other CVD films such as iO ₂ ), silicon nitride film (Si ₃ N ₄ ), and PSG film.

It is needless to say that the present invention is not limited to a low-pressure CVD apparatus, but can be applied to other CVD apparatuses that dope impurities, such as a normal-pressure CVD apparatus and a plasma CVD apparatus.

[0037]

Advantageous effects obtained by typical ones of the inventions disclosed in the present application will be briefly described.
It is as follows.

(1) A difference in activation energy between the dopant and the process gas is reduced by providing a dopant preheating chamber for heating the dopant to a predetermined temperature in the inner tube of the reaction chamber. Since the dopant can flow into the reaction chamber immediately after the dopant flows into the reaction chamber and be taken into the film, the dopant concentration can be made uniform for a plurality of semiconductor wafers.

(2) When the dopant is supplied through the dopant preheating chamber, the distance from the dopant supply port to each semiconductor wafer is reduced by supplying the dopant from the periphery of the semiconductor wafer in a shower form. Since the semiconductor wafers can be kept uniformly and can be uniformly doped into each semiconductor wafer, it is possible to reduce the variation in the concentration of the dopant in the film depending on the position in the reaction chamber.

(3) The pre-heating chamber for the dopant is divided into a plurality of sections.
By controlling the flow rate of the dopant in each of these divided dopant preheating chambers, the concentration of the dopant can be controlled with high precision, so that the uniformity of the dopant concentration is further improved. It becomes possible.

(4) According to the above (1) to (3), even when the activation energy difference between the dopant and the process gas is large in a plurality of semiconductor wafers in batch processing in the reaction chamber, each semiconductor wafer Thus, a CVD apparatus capable of forming a CVD film having a uniform dopant concentration can be obtained.

(5) According to the above (1) to (3), the uniformity of the dopant concentration in the CVD film can be improved.
It is possible to obtain a CVD apparatus capable of improving the processing ability due to the uniformity of the dopant.

(6) According to the above (1) to (3), it is possible to obtain a CVD apparatus capable of eliminating the step of diffusing the dopant in the manufacturing process of the semiconductor integrated circuit device.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a CVD apparatus that is Embodiment 1 of the present invention.

FIG. 2 is a schematic configuration diagram showing a reaction chamber used in the CVD apparatus of Example 1.

FIG. 3 is a schematic configuration diagram illustrating a reaction chamber used in a CVD apparatus that is Embodiment 2 of the present invention.

FIG. 4 is a schematic configuration diagram showing a reaction chamber used in a CVD apparatus which is an example of a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inner tube 2 Doping agent 3 Process gas 11 Reaction chamber 12 Gas supply control unit 13 Wafer heating unit 14 Vacuum exhaust unit 15 Inner tube 16, 16a Doping preheating room 17 Doping agent 18 Process gas 19 Opening 20 Mass flow controller

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-268026 (JP, A) JP-A-62-239537 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/205 H01L 21/31

Claims (3)

(57) [Claims] 1. A first pipe, a second pipe provided inside the first pipe and having a plurality of apertures, and between the first pipe and the second pipe. Using an apparatus having a formed and partitioned area and a wafer processing area provided inside the second tube for processing a plurality of semiconductor wafers, from one end side inside the second tube In the wafer processing area,
A first gas having a controlled flow rate is supplied, a second gas having a controlled flow rate is supplied to each of the plurality of divided regions, and the wafer processing region is supplied from the plurality of openings to the wafer processing region. Supplying a second gas, and reacting the first gas and the second gas to form a film on a semiconductor wafer installed in the wafer processing region. A method for manufacturing a semiconductor device. Wherein said first gas is a gas containing silicon, pre Kimaku method of manufacturing a semiconductor device according to claim 1, wherein the polysilicon film. 3. The method according to claim 1, wherein the second gas is preheated between the first tube and the second tube. .