JPH097911A - Fabricating apparatus for semiconductor - Google Patents

Abstract

PURPOSE: To provide an apparatus for fabricating a semiconductor which enables continuous processing of substrates in an air-tight atmosphere. CONSTITUTION: An apparatus for fabricating a semiconductor includes a laser annealing unit 1 which in turn has a chamber in which a substrate 4 to be processed is held in an air-tight atmosphere. A laser beam 5 is emitted to semiconductor material of the substrate 4 to thereby improve electrical characteristics of the substrate. Disposed upstream and downstream of the laser annealing unit 1 are a semiconductor film forming unit 2 and an insulation film forming unit 3. These units have each a chamber in which the substrate 4 is held in an air-tight atmosphere to be formed thereon with necessary thin films. These chambers communicate with each other through a gate valve 6, while maintaining their air-tight atmosphere. The substrate 4 is fed from the upstream chamber to the downstream chamber in the air-tight atmosphere according to a predetermined step sequence.

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 used for producing thin film semiconductor devices and the like. For more details,
The present invention relates to a semiconductor manufacturing apparatus that consistently performs film formation of a semiconductor thin film and laser annealing thereof.

[0002]

2. Description of the Related Art A thin film semiconductor device in which a thin film transistor having a semiconductor thin film as an active layer is integrally formed is used as a drive substrate of an active matrix type display device and is under active development. Conventionally, thin-film semiconductor devices are manufactured by a high temperature process like ordinary LSI devices, and high melting point quartz glass or the like having excellent heat resistance has been used for substrates. However, it is desired to reduce the substrate cost as the display device becomes larger and the like, and a low temperature process capable of adopting a low melting point glass or the like has been researched and developed. Laser annealing technology holds promise as part of the low-temperature process. In this technique, a semiconductor thin film formed on an insulating substrate is irradiated with laser light to be heated, and the semiconductor is crystallized in a cooling process to improve its characteristics. Generally, laser annealing is carried out in a vacuum atmosphere while the substrate is heated, and therefore a dedicated laser annealing apparatus has been put into practical use. On the other hand, a film forming apparatus such as a plasma CVD apparatus has been put into practical use in order to form a semiconductor thin film on an insulating substrate. Further, since a gate insulating film and the like are formed on the semiconductor thin film, a film forming apparatus such as an LPCVD apparatus has been put into practical use.

[0003]

Conventionally, a laser annealing apparatus and various film forming apparatuses used for manufacturing a thin film semiconductor device have been incorporated in a manufacturing line as individual units which are separated from each other. Therefore, it is necessary to repeat the vacuuming process and the heating process for each device. For example, a laser annealing apparatus is used to evacuate the chamber and heat the substrate. When forming a semiconductor thin film or a gate insulating film before and after this, steps such as evacuation and substrate heating have to be repeated completely separately, which requires a great deal of time in the manufacturing process of the thin film semiconductor device.

[0004]

SUMMARY OF THE INVENTION In view of the above problems of the prior art, it is an object of the present invention to provide a semiconductor manufacturing apparatus capable of improving the throughput of thin film semiconductor devices. The following measures were taken to achieve this purpose. That is, the semiconductor manufacturing apparatus according to the present invention comprises a combination of a laser annealing unit and at least one film forming unit. The laser annealing unit includes a chamber for holding a substrate to be processed in an airtight atmosphere, and irradiates a semiconductor included in the substrate with laser light to improve its electrical characteristics. The film forming unit also includes a chamber for holding the substrate in an airtight atmosphere, and forms a necessary thin film on the substrate. As a characteristic feature, a transfer means is provided, and each chamber is connected to each other while maintaining an airtight atmosphere, and the substrate is transferred from the previous chamber to the subsequent chamber in an airtight atmosphere in a predetermined process order. Preferably,
The transfer means is an in-line type transfer means that connects a plurality of chambers in series. Alternatively, the transfer means may be located at the center of a plurality of star-shaped chambers and interconnect the individual chambers.

In a specific configuration, the semiconductor manufacturing apparatus includes, for example, a semiconductor film forming unit and an insulator film forming unit in addition to the laser annealing unit. The semiconductor film forming unit has a first chamber and forms a thin film of a non-single crystalline semiconductor on an insulating substrate. The laser annealing unit includes a second chamber connected to the first chamber and irradiates the semiconductor with laser light to crystallize the semiconductor, thereby improving electrical characteristics. The insulator film forming unit includes a third chamber connected to the second chamber, and an insulating thin film is formed on the semiconductor in a stacked manner. Further, a temperature adjustment unit having an additional chamber interposed between the chambers adjacent to each other may be provided. This temperature adjustment unit heats / heats to adjust the difference in substrate temperature between processes.
Cool down. In addition, a load unit with an additional chamber located at the beginning of the process sequence that receives the substrate from the atmosphere side, and an unload unit with an additional chamber located at the end of the process sequence that discharges the substrate to the atmosphere side are provided. May be.

[0006]

According to the present invention, the semiconductor manufacturing apparatus includes a laser annealing unit for irradiating a semiconductor thin film forming a thin film semiconductor device with laser light. A film forming unit is connected to the laser annealing unit in such a manner that it can be vacuum-transferred to the front stage, the rear stage, or both of the process order (process order). This eliminates the need to perform vacuuming or substrate heating independently for each unit, and the throughput of the thin film semiconductor device can be greatly reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the drawings. 1 is a schematic block diagram showing a first embodiment of a semiconductor manufacturing apparatus according to the present invention. As shown in the figure, the semiconductor manufacturing apparatus includes a laser annealing unit 1
have. The laser annealing unit 1 includes a chamber for holding the substrate 4 to be processed in an airtight atmosphere, and irradiates the semiconductor light contained in the substrate 4 with laser light 5 to improve its electrical characteristics. In the illustrated example, the laser light 5
Is irradiated onto the substrate 4 in the chamber through a window 7 made of quartz or the like. The semiconductor manufacturing apparatus according to the present invention includes at least one film forming unit in addition to the laser annealing unit 1. This film forming unit is also the substrate 4
Is provided in an airtight atmosphere, and a necessary thin film is formed on the substrate 4. In this embodiment, a semiconductor film forming unit 2 and an insulator film forming unit 3 are provided before and after the laser annealing unit 1. Characteristically, the chambers are connected to each other by a gate valve 6 while maintaining an airtight atmosphere. A transfer means is incorporated so as to be able to pass through the gate valve 6, and the substrate 4 is transferred from the preceding chamber to the following chamber in an airtight atmosphere in a predetermined process order.

The semiconductor film forming unit 2 has a first chamber and forms a thin film of a non-single crystalline semiconductor on an insulating substrate 4. The semiconductor film forming unit 2 is composed of, for example, a plasma CVD apparatus and can form an amorphous silicon thin film. The laser annealing unit 1 includes a second chamber connected to the first chamber, and irradiates the semiconductor with the laser beam 5 to crystallize the semiconductor, thereby improving electrical characteristics. That is, amorphous silicon is converted into polycrystalline silicon. The insulator film forming unit 3 includes a third chamber and is formed by stacking an insulating thin film (for example, a gate insulating film) on a semiconductor. This insulator film forming unit 3 is, for example, an LP
It consists of a CVD device. As described above, in the present semiconductor manufacturing apparatus, the plasma CVD chamber of the semiconductor film forming unit 2, the vacuum chamber of the laser annealing unit 1, and the LPCVD chamber of the insulator film forming unit 3 are connected in series by the gate valve 6, and the substrate 4 Can be vacuum-transferred in-line.

The operation of the semiconductor manufacturing apparatus will be described in detail with reference to FIG. First, when manufacturing a thin film semiconductor device in which thin film transistors and the like are integrated, amorphous silicon is formed on the insulating substrate 4 by the plasma CVD method or the like in the semiconductor film forming unit 2. After that, the insulating substrate 4 is conveyed to the laser annealing unit 1 while maintaining the vacuum. The insulating substrate 4 moves in the chamber of the laser annealing unit 1 during this transportation process. During this movement, the laser light 5 is transmitted to the insulating substrate 4 through the quartz window 7.
Is irradiated. As a result, the amorphous silicon film formed on the insulating substrate 4 is melted and polycrystallized. Further, while maintaining the vacuum state, the insulating substrate 4 is used as the insulator film forming unit 3 in the subsequent stage.
Transported to Here, silicon oxide is deposited by LPCVD to obtain a gate insulating film. Since these semiconductor film forming process, laser annealing process, and insulator film forming process are all performed in a vacuum, it is not necessary to perform exhaust / intake for each process. Further, if the substrate temperature is set to be approximately the same in each process, the temperature raising / cooling process is not necessary. In addition,
In this embodiment, the film forming units are connected before and after the laser annealing process, but the present invention is not limited to this. For example, the film forming unit may be connected only to the former stage or the latter stage of the laser annealing unit. Generally, in the semiconductor manufacturing apparatus according to the present invention, a film forming unit may be connected to the laser annealing unit before or after the laser annealing unit, and the substrate may be vacuum-transferred between the chambers. Further, although the plasma CVD apparatus and the LPCVD apparatus are used in combination as the film forming unit in this embodiment, the present invention is not limited to this. For example, another film forming unit such as a sputtering device may be incorporated.
Also, the order of steps can be appropriately changed according to the process of the thin film semiconductor device.

FIG. 2 is a block diagram showing a specific structural example of the laser annealing unit incorporated in the first embodiment. The laser annealing unit 1 includes a chamber 8 and a heater 9 for heating is incorporated in the chamber 8.
A turbo molecular pump 10 and a dry pump 11 are connected in series to the chamber 8 so that the chamber 8 can be evacuated. Further, a gate valve 6 is provided at the boundary between the adjacent semiconductor film forming unit and the insulator film forming unit to partition the chamber of each unit. The gate valve 6 is closed during the film forming process to prevent interference between the chambers. When the film forming process is completed, the gate valve 6 is opened to enable the substrate transfer between the chambers. The semiconductor film forming unit 2
The plasma CVD chamber and the LPCVD chamber of the insulator film forming unit 3 basically have the same configuration as the chamber 8 of the laser annealing unit. The difference is that a parallel plate electrode for plasma generation, a process gas inlet, and the like are provided in the chamber.

FIG. 3 shows a concrete example of the structure of the substrate transfer mechanism (transfer means) incorporated in the chamber 8 of the laser annealing unit. The substrate transport mechanism is continuous through each chamber. The substrate 4 is set on the tray 12 and moves within each chamber and between chambers. Specifically, the tray transfer gear 14 inserted from the outside of the chamber 8 from above and below and the gear 13 carved on the tray 12 mesh with each other in the chamber 8, and the tray transfer gear 14 is rotated from the outside of the chamber 8. The substrate 4 is transported and moved. Laser annealing is performed during this transport movement. First, as a pre-stage, the insulating substrate 4 is put into the semiconductor film forming unit, the plasma CVD chamber is evacuated, and the substrate is heated to 450 ° C. In this state, amorphous silicon is deposited on the insulating substrate 4. After film formation, the substrate transport tray 12 is moved to the laser annealing unit. Then, laser annealing is performed while keeping the substrate 4 at 450 ° C. in the chamber 8. Specifically, laser light 5 is radiated during the transportation of the substrate to change the amorphous silicon into polycrystalline silicon 15.
Convert to At this time, two excimer laser light sources are used, and a region for two chips is irradiated with one shot along the width direction of the substrate 4. This reduces the takt time of laser annealing. After that, the substrate carrying tray 12 is moved to the LPCVD chamber of the insulator film forming unit to form a silicon oxide film. Here, the substrate temperature is lowered and the substrate is taken out into the atmosphere.

FIG. 4 is a schematic plan view showing another example of the laser annealing method. In this example, one laser light source is used to irradiate the insulating substrate 4 with a linear beam of laser light 5-2. The longitudinal dimension of the linear beam substantially matches the width dimension of the substrate 4. Laser beam 5 of linear beam during moving of substrate 4
-2 is irradiated continuously or in a pulsed manner, and the amorphous silicon is sequentially converted into polycrystalline silicon 15. Also in this example, it is sufficient to simply move the substrate 4 along one direction, the device structure is simplified, and only one laser light source is required.

FIG. 5 is a schematic plan view showing another example of the laser annealing method. In the example of FIG. 4, the optical system including the laser light source is fixed, but in this example, the substrate 4 is fixed while the laser light 5 is irradiated, while the laser light 5 is scanned two-dimensionally. Amorphous silicon is converted into polycrystalline silicon 15.

FIG. 6 shows a second embodiment of the semiconductor manufacturing apparatus according to the present invention. This semiconductor manufacturing apparatus is an in-line type. This apparatus is equipped with temperature adjusting units 18 on both sides of the central laser annealing unit 1. The temperature adjusting unit 18 is composed of an additional chamber interposed between adjacent chambers, and performs heating / cooling in order to adjust the temperature difference of the substrate 4 that occurs between the steps. Further, the load unit 16 located at the head of the process sequence is provided, and an additional chamber for receiving the substrate 4 from the atmosphere side is provided. Further, it includes an unload unit 17 located at the end of the process sequence, and uses an additional chamber to discharge the substrate 4 to the atmosphere side. The semiconductor film forming unit 2 is connected between the load unit 16 and the pre-stage temperature adjusting unit 18,
The insulator film forming unit 3 is interposed between the rear temperature adjusting unit 18 and the unload unit 17. All the units described above are connected in series by the gate valve 6. As a feature of this embodiment, a load unit 16 for vacuuming and heating the substrate is attached in front of the plasma CVD chamber of the semiconductor film forming unit 2. After the LPCVD chamber of the insulator film forming unit 3, an unload unit 17 for lowering the temperature and opening to the atmosphere is provided. By doing this, plasma CVD
The burden on the chamber and LPCVD chamber is lightened and the takt time is further reduced. Further, when the substrate temperatures of the plasma CVD process, the LPCVD process, and the laser annealing process are different, the tact time is further shortened by providing the temperature adjusting unit 18 for heating / cooling the substrate in advance.

FIG. 7 is a block diagram showing a third embodiment of the semiconductor manufacturing apparatus according to the present invention. In this example, the laser annealing unit 1, the semiconductor film forming unit 2, the insulator film forming unit 3, and the load lock unit 21 are arranged in a star shape. A robot unit 19 is arranged in the center of these units, and a gate valve 6 is provided for each peripheral unit.
Are individually connected via. A transfer robot 20 is incorporated in the robot unit 19 as a transfer means, and transfers the substrate 4 to the peripheral units according to a predetermined process sequence. For example, the substrate 4 which has been subjected to the film forming process in the semiconductor film forming unit 2 is conveyed to the laser annealing unit 1 by the robot 20. When the laser annealing process ends here, the robot 20 transfers the substrate 4 to the insulator film forming unit 3. After that, the substrate 4 is transferred to the load lock unit 21 by the robot 20 and taken out to the atmosphere side.

Finally, with reference to FIGS. 8 and 9, an example of a process for manufacturing a thin film semiconductor device using the semiconductor manufacturing apparatus according to the present invention will be described. In this example, a driving substrate incorporated in an active matrix type display device as a thin film semiconductor device is prepared. First, in step (a) of FIG. 8, a semiconductor thin film 102 made of amorphous silicon is formed on an insulating substrate 101. Next, in step (b), the semiconductor thin film 102 is irradiated with the laser beam 103 to convert the amorphous silicon into polycrystalline silicon. Subsequently, in step (c), a silicon oxide film is formed on the semiconductor thin film 102 to form a gate insulating film 104. The above process (a),
(B) and (c) can be continuously performed using the semiconductor manufacturing apparatus according to the present invention.

Next, in step (d), the semiconductor thin film 102
Then, the gate insulating film 104 is patterned in an island shape to form an element region of a thin film transistor. Moving to step (e) of FIG. 9, the gate electrode 1 is formed on the gate insulating film 104.
Pattern 05. In step (f), impurities 106 are ion-implanted by self-alignment using the gate electrode 105 as a mask to form a source region 107 and a drain region 108 in the semiconductor thin film 102. As a result, a top gate type thin film transistor is completed. Next, in step (g), the thin film transistor is covered with a first interlayer insulating film 109 made of PSG or the like. Finally, proceeding to the configuration (h), after forming a contact hole in the first interlayer insulating film 109, a metal film is formed and patterned into a predetermined shape to be processed into the wiring electrode 110. This wiring electrode 110
Is connected to the source region 107 of the thin film transistor. The second interlayer insulating film 1 also made of PSG or the like
11 is formed into a film. After opening the contact hole again,
A transparent conductive film such as ITO is formed and patterned into a predetermined shape to form the pixel electrode 112. The pixel electrode 112 is electrically connected to the drain region 108 of the thin film transistor through the contact hole.

[0018]

As described above, according to the present invention, the chambers constituting the laser annealing unit and the film forming unit are connected to each other while maintaining the airtight atmosphere, and the chambers from the previous chamber are connected in accordance with a predetermined process order. The substrate is transferred to the subsequent chamber in an airtight atmosphere. The vacuum connection between the chambers shortens the exhaust / intake time.
Also, for heating the substrate, as long as the process temperature is about the same, the heating / cooling time for heating / cooling can be short. In addition, since the film formation process is performed in a vacuum state after laser annealing, oxidation of the substrate surface and contamination of foreign substances can be prevented, and the process can be stabilized.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a semiconductor manufacturing apparatus according to the present invention.

FIG. 2 is a block diagram showing a specific configuration example of a laser annealing unit incorporated in the first embodiment.

FIG. 3 is a plan view showing a specific configuration example of a conveying means incorporated in the first embodiment.

FIG. 4 is a schematic plan view showing an example of a laser annealing method.

FIG. 5 is a schematic plan view showing another example of the laser annealing method.

FIG. 6 is a block diagram showing a second embodiment of the semiconductor manufacturing apparatus according to the present invention.

FIG. 7 is a block diagram showing a third embodiment of the semiconductor manufacturing apparatus according to the present invention.

FIG. 8 is a process chart showing an example of a method of manufacturing a thin film semiconductor device using the semiconductor manufacturing apparatus according to the present invention.

FIG. 9 is a process drawing similarly showing a method for manufacturing a thin film semiconductor device.

[Explanation of symbols]

 1 Laser Annealing Unit 2 Semiconductor Film Forming Unit 3 Insulator Film Forming Unit 4 Substrate 5 Laser Light 6 Gate Valve 8 Chamber 10 Turbo Molecular Pump 11 Dry Pump 12 Transport Tray 13 Gear 14 Transport Gear

Claims (6)

[Claims] 1. A laser annealing unit comprising a chamber for holding a substrate to be processed in an airtight atmosphere, and irradiating a semiconductor contained in the substrate with laser light to improve its electrical characteristics. Equipped with a chamber to hold in an airtight atmosphere,
At least one film forming unit for forming a necessary thin film on the substrate and each chamber are connected to each other while maintaining an airtight atmosphere, and the substrate is airtight from the previous chamber to the subsequent chamber according to a predetermined process sequence. A semiconductor manufacturing apparatus including a conveying unit that conveys below. 2. A semiconductor film forming unit having a first chamber for forming a thin film of a non-single crystalline semiconductor on an insulating substrate, and a second chamber connected to the first chamber. A laser annealing unit for improving electrical characteristics by irradiating the semiconductor with a laser beam to crystallize the semiconductor, and a third chamber connected to the second chamber are provided, and an insulating layer is provided on the semiconductor. The semiconductor manufacturing apparatus according to claim 1, further comprising: an insulator film forming unit that is formed by stacking thin films. 3. The semiconductor manufacturing apparatus according to claim 1, wherein the transfer means is an in-line transfer means that connects a plurality of chambers in series. 4. The semiconductor manufacturing apparatus according to claim 1, wherein the transfer means is located at the center of the plurality of star-shaped chambers and interconnects the individual chambers. 5. The method according to claim 1, further comprising a temperature adjusting unit having an additional chamber interposed between the chambers adjacent to each other, wherein heating / cooling is performed to adjust a difference in substrate temperature generated between processes. Semiconductor manufacturing equipment. 6. A load unit having an additional chamber located at the beginning of the process sequence for receiving a substrate from the atmosphere side,
2. The semiconductor manufacturing apparatus according to claim 1, further comprising an unload unit which is located at the end of the process sequence and has an additional chamber for discharging the substrate to the atmosphere side.