JP3757698B2 - Semiconductor manufacturing apparatus and semiconductor manufacturing system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor manufacturing apparatus for forming a semiconductor thin film on a substrate and a semiconductor manufacturing system in which a plurality of semiconductor manufacturing apparatuses are arranged in parallel.
[0002]
[Prior art]
As an application material for photoelectric devices in the blue and ultraviolet light regions, III [IUPAC (International Union of Pure and Applied Chemistry)], 1989 Inorganic Chemistry Nomenclature Revision, such as AlN, AlGaN, GaN, GaInN, InN etc. with wide band gap The group number is 13] -V [the group number according to the revised version is 15]. Currently, molecular beam epitaxy (MBE) and metal organic vapor phase epitaxy (MOCVD) are mainly used as methods for growing thin films. Of these, the MOCVD method is a method of causing a chemical reaction with the raw material transported in the gas phase and depositing the produced semiconductor on the substrate. By controlling the flow rate, it is easy to control the formation of ultrathin films and the mixed crystal ratio. Can be done. In principle, the MOCVD method is an industrially important method because crystals can be uniformly grown on a large-area substrate.
[0003]
However, the substrate temperature required for the growth of high-quality GaN crystals in the MOCVD method is as high as 900 to 1200 ° C., which limits the materials used for the substrate. In addition, since a semiconductor is stacked on an electrode, there is a limit to the degree of freedom in manufacturing a device configuration. On the other hand, the remote plasma MOCVD method, in which the source gas is decomposed by microwave or high frequency plasma oscillation, a gaseous organometallic compound is introduced into the remote plasma, and the generated semiconductor is deposited on the substrate is grown. This is an effective means for lowering the temperature.
[0004]
[Problems to be solved by the invention]
In this remote plasma MOCVD method, a manufacturing apparatus provided with a plurality of plasma generating means for independently controlling factors such as the type of carrier gas, pressure, and gas flow rate, which are problems in producing mixed crystals and multilayer films The film formation by is also performed. By preparing multiple plasma generation means and introducing hydrogen or the like as an auxiliary material from one side, the reduction effect of hydrogen radicals can reduce the incorporation of carbon into the semiconductor film, suppress film defects, and produce high-quality thin films. Can be produced.
[0005]
However, in a conventional semiconductor manufacturing apparatus using a plurality of plasma generating means, each plasma generating means is disposed in a different direction with respect to the substrate (see Japanese Patent Laid-Open No. 10-79348). For this reason, each activated gas enters the reaction vessel from different directions with respect to the substrate, and the flow of the gas in the reaction vessel is caused by the difference in the flow rate of the gas activated by each plasma generating means. The film thickness varies depending on the position on the substrate. For this reason, in order to make the film thickness uniform, a complicated apparatus such as a substrate rotation mechanism is required. In addition, a raw material gas that reacts with the raw material gas is introduced into the raw material gas activated by each plasma generating means, and the introduced raw material gas differs depending on the plasma generating means, and the reaction gas from each plasma generating means is used as a substrate When mixing immediately before, the reaction gas is not sufficiently mixed, and the composition of the thin film grown on the substrate varies depending on the position. This is not necessarily avoided even if a substrate rotation mechanism is provided.
[0006]
As described above, a portion that grows under optimized conditions is limited to a small area on the substrate, and a film having a uniform composition and film thickness cannot be formed on a large-area substrate.
[0007]
[Means for Solving the Problems]
The present invention has been made to solve the above-described problems, and is for forming a semiconductor thin film having a uniform composition and film thickness on a large-area substrate without using a complicated structure such as a substrate rotation mechanism. It is an object of the present invention to provide a manufacturing apparatus and a semiconductor manufacturing system using the apparatus.
[0008]
The present invention includes a substrate holder for holding a board, and a reaction vessel for forming a semiconductor film on the substrate, a first gas supply means for supplying a group V element source into the reaction vessel, the supply First plasma generating means for bringing the group V element source into a plasma state, and an organometallic compound containing a group III element source so as to react with the group V element source made into a plasma state by the first plasma generating means Second gas supply means for supplying the downstream of the first plasma generation means, third gas supply means for supplying an auxiliary material, second plasma generation means for activating at least the auxiliary material, And the first plasma generating means, the second plasma generating means, and the substrate holder are arranged in series along the supply direction of the group V element source .
[0009]
According to the present invention, the first plasma generating means, the second plasma generating means and the substrate holder, to be arranged in series along the feed direction of the group V element source, activated the The group V element (active species) is supplied from one direction, and the flow of the active species is not affected by the flow rate of the group III element source gas, and a thin film having a uniform thickness can be manufactured.
[0010]
The second plasma generating means is preferably an electrode having a donut shape or a slit .
[0011]
Further, at least one of the gas supply means may include a gas diffusing means having a hollow mesh shape or a slit shape having a gas ejection port. This gas diffusing means is preferably arranged in series with the two or more plasma generating means. The gas supply means connected to the gas diffusion means including the gas diffusion means can be moved up and down. The gas diffusion means can also serve as plasma generation means.
[0012]
The substrate holder can be movable in the reaction vessel.
[0013]
The present invention also provides a semiconductor manufacturing system in which any one of the plurality of semiconductor manufacturing apparatuses is arranged in parallel.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
[0015]
FIG. 1 shows a configuration of a semiconductor manufacturing apparatus 20 according to the first embodiment of the present invention. The semiconductor manufacturing apparatus 20 includes a reaction vessel 1 that is substantially cylindrical and can be evacuated. An exhaust port 2 is provided at the bottom of the reaction vessel 1. A substrate holder 3 for holding the substrate 5 is disposed in the reaction vessel 1. The substrate holder 3 includes a heater 4 for heating the substrate. A gas introduction pipe 11 is provided in the upper part of the reaction vessel 1. A quartz tube 6 is disposed concentrically inside the gas introduction tube 11. The gas introduction pipe 11 and the quartz pipe 6 constitute one gas supply means. A microwave waveguide 7 connected to a micro oscillator using a magnetron is provided so as to be orthogonal to the quartz tube 6. Further, a donut-shaped capacitively coupled high-frequency electrode 12 is disposed concentrically with the quartz tube 6 on the downstream side of the microwave waveguide 7 of the quartz tube 6. Further, as a gas supply means for supplying an auxiliary material used for controlling the energy of the raw material gas or the raw material gas to be activated or preventing film defects above the capacitively coupled high-frequency electrode 12 in the reaction vessel 1. The gas introduction pipe 8 is provided.
[0016]
A capacitively coupled high-frequency electrode 13 having a gas diffusion slit is provided downstream of the capacitively coupled high-frequency electrode 12. These capacitively coupled high-frequency electrodes 12 and 13 activate the gas in the gas introduction pipes 8 and 11.
[0017]
A gas diffusion means and gas diffusion meshes 14 and 15 as gas supply ports for supplying gas to the reaction vessel are arranged in series on the downstream side of the capacitively coupled high-frequency electrode 13. These gas diffusion meshes 14 and 15 are hollow and have gas outlets. The gas diffusion meshes 14 and 15 are connected to gas introduction pipes 9 and 10 as gas supply means for supplying a raw material gas, respectively. The gas introduction pipe 9 and the gas diffusion mesh 14, and the gas introduction pipe 10 and the gas diffusion mesh 15 constitute gas supply means.
[0018]
In this semiconductor manufacturing apparatus 20, the microwave waveguide 7 as the plasma generating means, the capacitively coupled high-frequency electrodes 12 and 13, the gas diffusion meshes 14 and 15, and the supply direction of the source gas that activates the substrate holder 3, In this case, they are arranged in series along the axial direction of the gas introduction tube 11 (or the quartz tube 6). That is, the raw material gas to be activated is supplied from one direction, that is, from the upper side of the reaction vessel 1, and the raw material that reacts with the activated raw material gas in the course of the supply path of the raw material gas to be activated to the substrate. Since the gas is supplied, sufficient mixing is obtained, and the gas flow direction is not affected by the gas flow rate, so that a film having a uniform and uniform thickness can be formed.
[0019]
In order to obtain a GaInN film using this semiconductor manufacturing apparatus 20, the substrate 5 is heated to 20 to 1200 ° C., for example, N ₂ as a raw material is introduced from the gas introduction tube 11, and 2.45 GHz is introduced into the microwave waveguide 7. The microwave is supplied and discharged in the quartz tube 6. Trimethylgallium gas is introduced from the gas introduction pipe 9 and trimethylindium gas is introduced from the gas introduction pipe 10 together with the carrier gas. Thus, the group III element is introduced downstream of the group V element. This group III element may be introduced at the most downstream or between the plurality of plasma generating means. Note that H ₂ as an auxiliary material may be introduced from the gas introduction pipe 8.
[0020]
By doing so, activated group III elements and group V elements exist on the substrate in an independently controlled state, and hydrogen atoms as auxiliary materials turn methyl groups into inert molecules such as methane. Therefore, carbon does not enter the semiconductor thin film, the film defects are suppressed, and the semiconductor film whose concentration and composition are controlled can be purified.
[0021]
FIG. 2 shows a configuration of a semiconductor manufacturing apparatus 30 according to the second embodiment of the present invention. Note that the same components as those of the semiconductor manufacturing apparatus 20 in FIG.
[0022]
The semiconductor manufacturing apparatus 30 includes a high-frequency coil 21 wound around the gas introduction tube 11 instead of the microwave waveguide 7. Further, instead of the capacitively coupled high-frequency electrode 12, a cylindrical capacitively coupled high-frequency electrode 22 having a donut shape and having a gas diffusion slit formed at the bottom is provided. The gas introduction tube 8 is connected to the capacitively coupled high-frequency electrode 22, and the gas introduced from the gas introduction tube 8 is activated by the capacitively coupled high-frequency electrode 22 and diffused from the slit. Further, a hollow gas diffusion mesh 23 having a gas outlet is provided instead of the capacitively coupled high-frequency electrode 13 in which a gas diffusion slit is formed so as to also serve as a high-frequency electrode.
[0023]
Also in this semiconductor manufacturing apparatus 30, the high-frequency coil 6, the capacitively coupled high-frequency electrode 22, the gas diffusion meshes 23 and 15 and the substrate holder 3 as plasma generating means are arranged in series along the axial direction of the gas introduction tube 11. The source gas to be activated is supplied from one direction, that is, from the upper side of the reaction vessel 1, and the source gas reacts with the activated source gas along the supply path of the source gas to be activated to the substrate. Therefore, sufficient mixing is obtained, and the gas flow is not affected by the gas flow rate, and a film having a uniform and uniform thickness can be formed.
[0024]
In the semiconductor manufacturing apparatuses 20 and 30, the discharge by the plasma generating means may be direct current discharge or alternating current discharge. In the case of alternating current discharge, low frequency discharge may be used in addition to high frequency discharge. Furthermore, in the case of high frequency discharge, it may be inductive or capacitive. Further, not only a micro-waveguide but also an electron cyclotron resonance type or helicon plasma type waveguide may be used. The combination of the plasma generating means is arbitrary, and is not limited to the combination of the microwave waveguide and the capacitively coupled high-frequency electrode, and the high-frequency coil and the capacitively coupled high-frequency electrode.
[0025]
When two or more types of plasma generating means are used in one space, it is necessary to allow discharge to occur simultaneously at the same pressure, and a pressure difference is generated between a portion where plasma is generated and the vicinity of a substrate on which a semiconductor is formed. It may be provided. When these pressures are made the same, different types of plasma generating means, for example, the microwave waveguide 7 and the capacitively coupled high-frequency electrodes 12 and 13 as shown in FIG. It is possible to control the film quality.
[0026]
The gas introduction pipe 9 and the gas diffusion mesh 14 or 23 and the gas introduction pipe 10 and the gas diffusion mesh 15 may be movable up and down. Further, the substrate holder 3 may rotate or be movable up and down.
[0027]
In the semiconductor manufacturing apparatuses 20 and 30, the gas introduction pipe 11 is disposed immediately above the reaction vessel 1, but the gas introduction pipe 11 may be inclined obliquely.
[0028]
Furthermore, although the gas diffusion mesh is used in the semiconductor manufacturing apparatuses 20 and 30, a box-shaped gas diffusion means in which a plurality of slits are formed at the bottom may be used instead of the mesh. Further, the gas diffusing means may be omitted if the gas supply ports (lower end portions) of the gas introduction pipes 9 and 10 are arranged in the vicinity of the raw material gas supply path to be activated. In this case, the gas supply port does not necessarily have to be arranged in series with the plasma generating means or the substrate holder.
[0029]
Further, in one semiconductor manufacturing apparatus, two or more of the plurality of plasma generating means may be in series, and not all of the plasma generating means may be in series.
[0030]
FIG. 3 shows a configuration of a semiconductor manufacturing system 40 according to the third embodiment of the present invention. The same components as those of the semiconductor manufacturing apparatuses 20 and 30 are denoted by the same reference numerals and description thereof is omitted. The semiconductor manufacturing system 40 includes two semiconductor manufacturing units 43 and 44 and a connection chamber 41 for connecting these units. A gate valve 42 is provided between the connection chamber 41 and each unit. The semiconductor manufacturing units 43 and 44 are provided with the microwave waveguide 7 instead of the high-frequency coil 21, and one substrate holder 3 that can be moved horizontally between the units is shared by the semiconductor manufacturing units 43 and 44. Except for this, it is the same as the semiconductor manufacturing apparatus 30.
[0031]
FIG. 4 shows the configuration of a semiconductor manufacturing system 50 according to the third embodiment of the present invention. The same components as those of the semiconductor manufacturing apparatuses 20 and 30 are denoted by the same reference numerals and description thereof is omitted. The semiconductor manufacturing system 50 includes three semiconductor manufacturing units 51, 52, and 53. These semiconductor manufacturing units 51, 52, 53 are provided with the microwave waveguide 7 instead of the high-frequency coil 21, and one substrate holder 3 that is movable between the units is the semiconductor manufacturing units 51, 52, 53. And the same as that of the semiconductor manufacturing apparatus 30 except that one reaction vessel 54 whose internal space is closed by an openable / closable threshold plate 56 is used instead of the three reaction vessels 1. is there.
[0032]
By using such a semiconductor manufacturing system, it is possible to stack layers having different compositions in arbitrary thicknesses in a short time using different activation conditions (for example, discharge power, flow rate of source gas, doping element, etc.). It becomes possible.
[0033]
【The invention's effect】
The present invention can provide a manufacturing apparatus for forming a semiconductor thin film having a uniform composition and film thickness on a large-area substrate, and a semiconductor manufacturing system using this apparatus.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a semiconductor manufacturing apparatus according to a first embodiment of the present invention.
FIG. 2 is a configuration diagram of a semiconductor manufacturing apparatus according to a second embodiment of the present invention.
FIG. 3 is a configuration diagram of a semiconductor manufacturing system according to a third embodiment of the present invention.
FIG. 4 is a configuration diagram of a semiconductor manufacturing system according to a fourth embodiment of the present invention.
[Explanation of symbols]
1 Reaction vessel 3 Substrate holder 6 Quartz tube (gas supply means)
7 Microwave waveguide (plasma generating means)
8 Gas introduction pipe (gas supply means)
9 Gas introduction pipe (gas supply means)
10 Gas introduction pipe (gas supply means)
11 Gas introduction pipe (gas supply means)
12 Capacitively coupled high-frequency electrode (plasma generating means)
13 Capacitively coupled high-frequency electrode (plasma generating means, gas diffusion means)
14 Gas diffusion mesh (gas diffusion means)
15 Gas diffusion mesh (gas diffusion means)
20 Semiconductor Manufacturing Equipment 21 High Frequency Coil (Plasma Generator)
22 Capacitively coupled high-frequency electrode (plasma generating means)
23 Gas diffusion mesh (gas diffusion means, plasma generation means)
DESCRIPTION OF SYMBOLS 30 Semiconductor manufacturing apparatus 40 Semiconductor manufacturing system 43 Semiconductor manufacturing unit 44 Semiconductor manufacturing unit 50 Semiconductor manufacturing system 51 Semiconductor manufacturing unit 52 Semiconductor manufacturing unit 53 Semiconductor manufacturing unit

Claims (8)

A substrate holder for holding a board,
A reaction vessel for forming a semiconductor film on the substrate;
First gas supply means for supplying a group V element source into the reaction vessel;
First plasma generating means for bringing the supplied group V element source into a plasma state ;
Second gas supply means for supplying an organometallic compound containing a group III element source downstream of the first plasma generation means so as to react with a group V element source made into a plasma state by the first plasma generation means When,
A third gas supply means for supplying an auxiliary material;
Second plasma generating means for activating at least the auxiliary material ,
The semiconductor manufacturing apparatus, wherein the first plasma generating means, the second plasma generating means, and the substrate holder are arranged in series along a supply direction of the group V element source . The semiconductor manufacturing apparatus according to claim 1 , wherein the second plasma generating means is a donut-shaped electrode . The second plasma generation means semiconductor manufacturing apparatus according to claim 1 Symbol mounting an electrode provided with a slit. 4. The semiconductor manufacturing apparatus according to claim 1, wherein at least one of the first to third gas supply means includes a gas diffusion means having a hollow mesh shape or a slit shape having a gas ejection port . 5. The semiconductor manufacturing apparatus according to claim 4 , wherein a gas supply means including the gas diffusion means is movable up and down. 6. The semiconductor manufacturing apparatus according to claim 4, wherein the gas diffusion means also serves as plasma generation means.   The semiconductor manufacturing apparatus according to claim 1, wherein the substrate holder is movable in the reaction vessel.   A semiconductor manufacturing system in which a plurality of semiconductor manufacturing apparatuses according to claim 1 are arranged in parallel.

Images