JPH09289321A - Semiconductor device manufacturing method and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a seamless high-uniformity semiconductor device by forming an amorphous semiconductor thin film on an insulative substrate and irradiating a laser beam on this semiconductor thin film to selectively crystallize this amorphous semiconductor film, using the holography. SOLUTION: An amorphous Si (a-Si) 3 is formed on a substrate 1 having a SiO2 film as a buffer layer 2 and etched with leaving the a-Si only at a transistor forming area. The substrate 1 is carried to a laser irradiating chamber by a substrate conveyer system and a XeCl excimer laser beam of 308nm wavelength is selectively irradiated on the transistor-forming area only, using a holography mask at an energy density of 100-500mJ/cm<2> to crystallize the a-Si on the substrate 1 into a polycrystalline Si 4. Since the laser beam is irradiated on the semiconductor device-forming area only, a seamless high-uniformity semiconductor device can be formed efficiently.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device applied to a liquid crystal display device, a sensor array, an SRAM, etc. and a manufacturing apparatus thereof.

[0002]

2. Description of the Related Art As an example of a conventional semiconductor device, a polysilicon thin film transistor being developed for a liquid crystal display device will be described below with reference to the drawings.

In recent years, in the field of liquid crystal display using thin film transistors, a poly-polycrystalline silicon thin film transistor (hereinafter, referred to as "polycrystalline silicon thin film transistor" (hereinafter referred to as "600") which can be manufactured at a relatively low temperature (about 600 ° C or less), which can use an inexpensive glass substrate instead of an expensive quartz substrate. "Low temperature po
abbreviated as “ly-Si TFT”) has been attracting attention. For example, `` Proceedings of the Twelfth International Disp
A low temperature poly-Si TFT described in "Lay Research Conference (1992) pp 565-568" will be briefly described as a conventional example with reference to a schematic sectional view of FIG.

In the method of manufacturing a low temperature poly-Si TFT of this conventional example, first, an amorphous silicon layer is deposited on the entire surface of a substrate 1, and then a KrF excimer laser is irradiated to locally deposit the amorphous silicon layer on the substrate. After heating and melting to crystallize to obtain polycrystalline silicon, a desired island-shaped patterned polycrystalline silicon 4 is obtained by photolithography and etching. Next, a SiO ₂ layer is formed as the gate insulating layer 5.
Next, the gate electrode 7 is formed of polycrystalline silicon (hereinafter, poly-Si).
Then, an impurity serving as a donor or an acceptor is introduced by ion implantation using the gate electrode 7 as a mask to form a source region 8 and a drain region 9.
Then, after forming the interlayer insulating layer 10, the contact hole 11
To form Thereafter, hydrogenation is performed to compensate for defects in the poly-Si layer. Finally source electrode 12 and drain electrode
By forming 13, a low temperature poly-Si TFT is manufactured.

Further, since a poly-Si TFT has a larger field effect mobility than a transistor using amorphous silicon as a semiconductor layer, P-channel and N-channel transistors can be formed by selectively using boron or phosphorus as impurities. Since it can be created selectively, CMO
The S circuit can be formed, and the drive circuit of the pixel transistor can be formed on the same substrate.

[0006]

When the conventional low temperature poly-Si TFT shown in FIG. 5 is manufactured, in the example shown in FIG. 5, the laser beam is irradiated linearly or rectangularly to irradiate the entire surface with the laser. Irradiate while overlapping the laser beams processed into. Therefore, it is inefficient because the laser beam is applied to the region where the transistor is not actually formed. Further, since irradiation is performed while overlapping, there is a problem that it is difficult to form a uniform transistor because the characteristics of the transistor vary near the joint between the laser beams.

Further, after crystallization by laser beam irradiation, photolithography and etching steps are performed before the gate insulating layer is deposited, so that it is difficult to keep the semiconductor / insulating layer interface clean and the number of steps. There is also a problem that there are many.

The present invention solves the above problems, and
An object of the present invention is to provide a method of manufacturing a semiconductor device that is low in cost and excellent in performance, and a manufacturing apparatus thereof.

[0009]

In order to solve the above problems and to achieve the object, the present invention provides a semiconductor device manufacturing method, comprising:
A step of forming a semiconductor thin film containing amorphous as a main component on an insulating substrate or a semiconductor substrate via an insulating layer, and irradiating the semiconductor thin film containing the amorphous with a laser beam using holography Selectively crystallizing the semiconductor thin film containing amorphous as a main component, selectively removing the semiconductor thin film containing amorphous as a main component in the laser beam non-irradiated region, and insulating Forming a layer,
Characterized by including a step of selectively forming a gate electrode, a step of introducing an impurity for forming a source / drain region into the semiconductor thin film, and a step of selectively forming a source / drain electrode Is.

The semiconductor device manufacturing apparatus of the present invention is
It has at least a means for selectively irradiating a laser beam using holography under reduced pressure or under normal pressure, a means for depositing a desired thin film, and a means for etching a desired thin film by plasma of a reaction gas, which is exposed to the atmosphere. It is characterized in that it can be continuously processed without any treatment.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A method of manufacturing a semiconductor device according to claim 1 of the present invention comprises a step of forming a non-single crystal semiconductor thin film on an insulating substrate or a semiconductor substrate with an insulating layer interposed therebetween.
It is characterized by including a step of selectively crystallizing or recrystallizing the non-single-crystal semiconductor thin film by irradiating the non-single-crystal semiconductor thin film with a laser beam by using holography. According to the present invention, the laser beam is applied only to the portion where the semiconductor device is originally formed, which is efficient, and at the same time, there is an effect that a highly uniform semiconductor device can be manufactured because there is no joint.

A method of manufacturing a semiconductor device according to claim 2 is
A step of forming a semiconductor thin film containing amorphous as a main component on an insulating substrate or a semiconductor substrate via an insulating layer, and irradiating the semiconductor thin film containing the amorphous with a laser beam using holography And selectively crystallizing the amorphous semiconductor-based semiconductor thin film, and selectively removing the amorphous semiconductor-based semiconductor thin film in the laser beam non-irradiated region. It is characterized by. According to the present invention, since the photolithography process can be omitted, there is an effect that a low cost and highly uniform semiconductor device can be manufactured.

A method of manufacturing a semiconductor device according to claim 3 is
The semiconductor thin film containing amorphous as a main component is removed by exposing it to plasma containing a gas having a structure in which at least hydrogen or a part or all of hydrogen in a hydrocarbon is replaced by fluorine. Is a method for manufacturing a semiconductor device. According to the present invention, since the photolithography process can be omitted, there is an effect that a low cost and highly uniform semiconductor device can be manufactured.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a semiconductor device.
A step of forming a semiconductor thin film containing amorphous as a main component on an insulating substrate or a semiconductor substrate via an insulating layer, and irradiating the semiconductor thin film containing the amorphous with a laser beam using holography Selectively crystallizing the semiconductor thin film containing amorphous as a main component, selectively removing the semiconductor thin film containing amorphous as a main component in the laser beam non-irradiated region, and insulating Forming a layer,
Characterized by including a step of selectively forming a gate electrode, a step of introducing an impurity for forming a source / drain region into the semiconductor thin film, and a step of selectively forming a source / drain electrode Is. According to the present invention, since the photolithography process can be omitted, there is an effect that a semiconductor device having low cost and high uniformity can be manufactured.

A semiconductor device manufacturing apparatus according to claim 5 is
It is characterized by having at least a means for selectively irradiating a laser beam using holography under reduced pressure or under normal pressure. According to the present invention, it is possible to provide a manufacturing apparatus that is efficient because a laser beam is originally irradiated only to a portion where a semiconductor device is originally formed, and at the same time, a semiconductor device having high uniformity can be manufactured because there is no joint. .

An apparatus for manufacturing a semiconductor device according to claim 6 is
Characterized by having at least means for selectively irradiating a laser beam using holography under reduced pressure or under normal pressure and means for etching a desired thin film by plasma of a reaction gas, and being capable of performing continuous treatment without exposure to the atmosphere It is what According to the present invention, since the photolithography process can be omitted, there is an effect that it is possible to provide a manufacturing apparatus that can manufacture a highly uniform semiconductor device at low cost.

A semiconductor device manufacturing apparatus according to claim 7 is
It is characterized in that it has at least a means for selectively irradiating a laser beam using holography under reduced pressure or under normal pressure and a means for depositing a desired thin film, and can perform continuous processing without exposing to the atmosphere. . According to the present invention, since the semiconductor / insulating layer interface is clean, there is an effect that it is possible to provide a manufacturing apparatus capable of manufacturing a semiconductor device having high performance, high reliability, and high uniformity.

A semiconductor device manufacturing apparatus according to claim 8 is:
It has at least a means for selectively irradiating a laser beam using holography under reduced pressure or under normal pressure, a means for depositing a desired thin film, and a means for etching a desired thin film by plasma of a reaction gas, which is exposed to the atmosphere. It is characterized in that it can be continuously processed without any treatment.
According to the present invention, a photolithography process can be omitted, so that it is possible to provide a manufacturing apparatus that is low in cost and that has a clean semiconductor / insulating layer interface, has high performance, high reliability, and can manufacture highly uniform semiconductor devices. Have an effect.

Each embodiment of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a process sectional view for explaining a method for manufacturing a semiconductor device according to a first embodiment of the present invention, and FIG. 2 illustrates a device for manufacturing a semiconductor device according to the present invention. 3 is a schematic configuration diagram for this, and will be described in order below.

As shown in the process sectional view of FIG. 1, a substrate coated with a SiO ₂ film as a buffer layer 2 for preventing diffusion of impurities in the glass substrate (# 7059 glass manufactured by Corning).
Amorphous silicon (hereinafter abbreviated as a-Si) 3 with a film thickness of 30 to 100 nm is formed on 1 by a low pressure CVD method using, for example, disilane (Si ₂ H ₆ ) as a source gas, and photolithography and etching are performed. A-Si3 is left only where the transistor is formed by (FIG. 1 (a)).

Then, the substrate 1 is set in the semiconductor device manufacturing apparatus shown in FIG. This semiconductor device manufacturing apparatus includes a load lock chamber 101, an unload lock chamber 102, a substrate transfer chamber 103, a substrate transfer system 104, a quartz window for excimer laser transmission, a holographic mask, and an alignment mechanism of a polycrystalline thin film forming apparatus. And a laser irradiation chamber 105 having a stage having a stage, a plasma CVD chamber 106 for depositing a thin film by plasma CVD, and a sputtering chamber 107 for depositing a thin film by sputtering. However, a vacuum exhaust system, a gas introduction system, a laser, an optical system, etc. are actually required, but they are omitted.

Load lock chamber of this polycrystalline thin film forming apparatus
First, the substrate 1 is transferred to the laser irradiation chamber 105 via the substrate transfer system 104 via the substrate transfer chamber 103 and 101, and a-Si on the substrate is crystallized to obtain polycrystalline silicon 4 (FIG. 1).
(b)).

In this embodiment, an XeCl excimer laser having a wavelength of 308 nm is used, and only a transistor forming portion is selectively irradiated with crystallization by using a holographic mask with an energy density of 100 to 500 mJ / cm ² for crystallization. Then, the substrate 1
Is transferred to the plasma CVD chamber 106 through the substrate transfer chamber 103, and TEOS (Tetraethylorthosilicate: (C ₂ H ₅ O) ₄ S
SiO ₂ is deposited on the entire surface as the gate insulating layer 5 by the plasma CVD method using i) as a source gas. Then, the substrate 1 is again transported to the sputtering chamber 107 via the substrate transfer chamber 103.
Then, chromium (Cr) 6 is deposited by the sputtering method (FIG. 1 (c)).

After that, the substrate 1 is placed in the unload lock chamber 102.
It is taken out from the manufacturing apparatus of this semiconductor device via. And
The Cr 6 is patterned by photolithography and etching to form the gate electrode 7. Then, in order to form the source / drain regions by using the gate electrode 7 in this state as a mask at the time of doping, an impurity element serving as a donor or an acceptor is implanted by an ion doping method without mass separation, and the source / drain regions are formed. Make 8 and 9 (Fig. 1 (d)).

300 to activate the introduced impurities
Heat treatment is performed at about 600 ° C., rapid thermal annealing, excimer laser irradiation, or the like. Then, after this, as the interlayer insulating layer 10, for example, SiO 2 is formed by the AP-CVD method.
₂ film is formed, contact hole 11 is formed, source
As the drain electrodes 12 and 13, for example, aluminum (A
l) is deposited by sputtering and then patterned by photolithography etching to give poly-Si
The TFT is completed (FIG. 1 (e)).

In the first embodiment, a-Si by low pressure CVD method is used, but plasma C other than low pressure CVD is used.
It may be formed by a VD method, a sputtering method, or the like. Although the polycrystalline silicon 4 is used as the semiconductor material, other semiconductor materials such as germanium (Ge) and silicon-germanium alloy (SiGe) may be used.

In the first embodiment, the XeCl excimer laser is used as the laser, but other excimer lasers such as ArF and KrF or Ar lasers may be used.

After the crystallization, a step of compensating for the grain boundary of the polycrystalline silicon 4 or the trap level in the grain to enhance the crystallinity by exposing to hydrogen plasma or performing hydrogen annealing is added. Is desirable.

Plasma CV is used as the gate insulating layer 5.
Although SiO _{2 according} to the D method was used, other methods such as AP-
CVD (Atomospheric Pressure CVD) SiO ₂ or LTO by method (Low Temperature Oxide), it is needless to say may be SiO ₂ or the like by ECR-CVD. Further, silicon nitride, tantalum oxide, aluminum oxide or the like can be used as a material, and a laminated structure of these thin films may be adopted.

Although the gate electrode 7 is made of Cr and the source electrode 12 and the drain electrode 13 are made of aluminum (Al), aluminum (Al) and tantalum (T) are used.
a), molybdenum (Mo), chromium (Cr), titanium (Ti), or other metals or alloys thereof, or poly-Si or poly-SiGe alloys containing a large amount of impurities, or transparent conductive layers such as ITO. good.

It is also possible to adopt an LDD structure in order to improve the off characteristic. It is also possible to selectively form P-channel and N-channel transistors by selectively using boron or arsenic as an impurity as an impurity and phosphorus or aluminum as a donor to form a CMOS circuit on a substrate. Needless to say.

(Embodiment 2) FIG. 3 is a process sectional view for explaining a method for manufacturing a semiconductor device according to a second embodiment of the present invention, and FIG. 4 illustrates a device for manufacturing a semiconductor device according to the present invention. FIG. 3 is a schematic configuration diagram for doing so, which will be described in order below.

As shown in the process cross-sectional view of FIG. 3, a substrate coated with a SiO ₂ film as a buffer layer 2 for preventing the diffusion of impurities in the glass substrate (# 7059 glass manufactured by Corning).
1 is set in the semiconductor device manufacturing apparatus of the present invention. As shown in FIG. 4, this semiconductor device manufacturing apparatus includes a load lock chamber 101, an unload lock chamber 102,
Substrate transfer chamber 103, substrate transfer system 104, laser irradiation chamber 105 having a quartz window for excimer laser transmission and a stage having a holographic mask and an alignment mechanism, plasma CVD chamber 106 for depositing amorphous silicon deposition, sputtering And a substrate heating chamber 108 and a reactive ion etching chamber 109 for depositing a thin film. However, a vacuum exhaust system, a gas introduction system, a laser, an optical system, etc. are actually required, but they are omitted.

Load lock chamber of this polycrystalline thin film forming apparatus
First, the substrate 1 is transferred to the substrate heating chamber through the substrate 101 and the substrate transfer chamber 103.
At 108, raise to an appropriate temperature of 200-400 ° C. Then, the substrate 1 is transferred to the plasma CVD chamber 106 for depositing amorphous silicon by the substrate transfer system 104, and silane (SiH4) is added.
Film thickness of 30 to 10 by plasma CVD method using
Amorphous silicon (hereinafter abbreviated as a-Si) 3 is formed at 0 nm (FIG. 3A).

After that, the substrate 1 is transferred to the laser irradiation chamber 105 through the substrate transfer chamber 103, and a-Si3 on the substrate is crystallized. In the present embodiment, an XeCl excimer laser having a wavelength of 308 nm is used, and only a transistor forming portion is selectively irradiated with an energy density of 100 to 500 mJ / cm ² using a holographic mask to crystallize to obtain polycrystalline silicon 4. FIG. 3B).

Next, the substrate 1 is transferred to the reactive ion etching chamber 109 via the substrate transfer chamber 103. Then, using the etching effect of hydrogen plasma, only the amorphous silicon 4 is selectively removed by etching (FIG. 3).
(c)).

After that, the substrate 1 is transferred to the plasma CVD chamber 106 through the substrate transfer chamber 103, and TEOS (Tetraethylor)
TiOsilicate: (C ₂ H ₅ O) ₄ Si) is used as a source gas to deposit SiO ₂ as a gate insulating layer 5 on the entire surface by a plasma CVD method. Then, the substrate 1 is again transported to the sputtering chamber 107 via the substrate transfer chamber 103. Then, chromium (Cr) 6 is deposited by the sputtering method (FIG. 3 (d)).

Thereafter, the substrate 1 is placed in the unload lock chamber 102.
It is taken out from the manufacturing apparatus of this semiconductor device via. And
The Cr 6 is patterned by photolithography and etching to form the gate electrode 7. Then, in order to form the source / drain regions by using the gate electrode 7 in this state as a mask at the time of doping, the impurity element serving as the donor or the acceptor is implanted by the ion doping method without mass separation, and the source / drain region is formed. Make 8 and 9 (Fig. 3 (e)).

300 to activate the introduced impurities
Heat treatment is performed at about 600 ° C., rapid thermal annealing, excimer laser irradiation, or the like. Then, after this, as the interlayer insulating layer 10, for example, SiO 2 is formed by the AP-CVD method.
₂ is formed, contact holes 11 are formed, and source / drain electrodes 12 and 13 are made of, for example, aluminum (Al).
Is deposited by sputtering, and then photolithography
By patterning by etching, poly-Si T
The FT is completed (Fig. 3 (f)).

In this embodiment, plasma CVD is used.
Although a-Si by the method is used, it may be formed by a low pressure CVD method other than the plasma CVD method, a sputtering method, or the like. Although polycrystalline silicon is used as the semiconductor material, other semiconductor materials such as germanium (Ge) and silicon-germanium alloy (SiGe) may be used.

Further, in the present embodiment, X is used as the laser.
Although the eCl excimer laser is used, another excimer laser such as ArF or KrF or an Ar laser may be used.

In addition, after crystallization, a step of compensating for a grain boundary of the polycrystalline silicon 4 or a trap level in the grain to enhance crystallinity by adding hydrogen plasma or performing hydrogen annealing is added. Is desirable.

Plasma CV is used as the gate insulating layer 5.
Although SiO _{2 according} to the D method was used, other methods such as AP-
Needless to say, SiO ₂ by the CVD (Atomospheric Pressure CVD) method, LTO (Low Temperature Oxide), SiO ₂ by the ECR-CVD, or the like may be used. Further, silicon nitride, tantalum oxide, aluminum oxide or the like can be used as a material, and a laminated structure of these thin films may be adopted.

Although Cr was used as the material of the gate electrode 7 and aluminum (Al) was used as the material of the source electrode 12 and the drain electrode 13, aluminum (Al), tantalum (T
a), molybdenum (Mo), chromium (Cr), titanium (Ti), or other metals or alloys thereof, or poly-Si or poly-SiGe alloys containing a large amount of impurities, or transparent conductive layers such as ITO. good. Also, it is possible to adopt an LDD structure in order to improve the off characteristics. It is also possible to selectively form P-channel and N-channel transistors by selectively using boron or arsenic as an impurity as an impurity and phosphorus or aluminum as a donor to form a CMOS circuit on a substrate. Needless to say.

[0046]

As described above, according to the present invention, since the laser beam is applied only to the portion where the semiconductor device is formed, it is efficient and, at the same time, it is possible to manufacture a semiconductor device having high uniformity. . Further, since the photolithography process can be omitted, a semiconductor device with low cost and high uniformity can be manufactured. Furthermore, since the semiconductor / insulating layer interface is clean, a semiconductor device with high performance, high uniformity, and high reliability can be manufactured.

[Brief description of drawings]

FIG. 1 is a schematic cross sectional view for each main step for explaining a method for manufacturing a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram for illustrating the semiconductor device manufacturing apparatus according to the first embodiment of the present invention.

FIG. 3 is a schematic cross sectional view for each main step for explaining the method for manufacturing the semiconductor device in the second embodiment of the present invention.

FIG. 4 is a conceptual diagram for explaining a semiconductor device manufacturing apparatus according to a second embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view of a thin film transistor as an example of a conventional semiconductor device.

[Explanation of symbols]

1 ... Substrate, 2 ... Buffer layer, 3 ... Amorphous silicon
(a-Si), 4 ... Polycrystalline silicon, 5 ... Gate insulating layer, 6 ... Chrome (Cr), 7 ... Gate electrode, 8 ... Source region, 9 ... Drain region, 10 ... Interlayer insulating layer, 11
… Contact hole, 12… Source electrode, 13… Drain electrode, 101… Load lock chamber, 102… Unload lock chamber, 103… Substrate transfer chamber, 104… Substrate transfer system,
105 ... Laser irradiation chamber, 106 ... Plasma CVD chamber, 10
7 ... Sputtering room, 108 ... Substrate heating room, 109 ... Reactive ion etching room.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H01L 21/3065 H01L 29/78 627B

Claims (8)

[Claims] 1. A step of forming a non-single-crystal semiconductor thin film on an insulating substrate or a semiconductor substrate with an insulating layer interposed therebetween, and irradiating the non-single-crystal semiconductor thin film with a laser beam using holography to obtain the non-single-crystal film. A method of manufacturing a semiconductor device, comprising the step of selectively crystallizing or recrystallizing a crystalline semiconductor thin film. 2. A step of forming a semiconductor thin film containing amorphous as a main component on an insulating substrate or a semiconductor substrate with an insulating layer interposed therebetween, and holography is used for the semiconductor thin film containing amorphous as a main component. Laser beam irradiation to selectively crystallize the amorphous semiconductor-based semiconductor thin film, and selectively remove the amorphous semiconductor-based semiconductor thin film in the laser beam non-irradiated region A method of manufacturing a semiconductor device, comprising: 3. The semiconductor thin film containing amorphous as a main component is removed by exposing it to a plasma containing a gas having a structure in which at least a part or all of hydrogen or hydrocarbon is replaced by fluorine. The method for manufacturing a semiconductor device according to claim 2. 4. A step of forming a semiconductor thin film containing an amorphous component as a main component on an insulating substrate or a semiconductor substrate with an insulating layer interposed therebetween, and holography is used for the semiconductor thin film containing the amorphous component as a main component. Laser beam irradiation to selectively crystallize the amorphous semiconductor-based semiconductor thin film, and selectively remove the amorphous semiconductor-based semiconductor thin film in the laser beam non-irradiated region A step of forming an insulating layer, a step of selectively forming a gate electrode,
A method of manufacturing a semiconductor device, comprising: a step of introducing impurities for forming source / drain regions into the semiconductor thin film; and a step of selectively forming source / drain electrodes. 5. An apparatus for manufacturing a semiconductor device, comprising at least a means for selectively irradiating a laser beam using holography under reduced pressure or under normal pressure. 6. At least a means for selectively irradiating a laser beam using holography under reduced pressure or normal pressure and a means for etching a desired thin film by plasma of a reaction gas are provided, and the means is continuously exposed to the atmosphere. An apparatus for manufacturing a semiconductor device, which can be processed into 7. A method for selectively irradiating a laser beam by using holography under reduced pressure or under normal pressure and a means for depositing a desired thin film, which are capable of being continuously processed without being exposed to the atmosphere. And a semiconductor device manufacturing apparatus. 8. A means for selectively irradiating a laser beam using holography under reduced pressure or normal pressure, means for depositing a desired thin film, and means for etching a desired thin film by plasma of a reaction gas. The semiconductor device manufacturing apparatus is characterized in that it can be continuously processed without being exposed to the atmosphere.