KR20070006179A - Apparatus of forming a layer for manufacturing a semiconductor device - Google Patents

Abstract

An apparatus for forming a layer for fabricating a semiconductor is provided to simultaneously irradiate light to a plurality of substrates by using a plurality of beam splitters. A plurality of substrates(W) are received in a reaction chamber(104). Thin films are formed on the substrates by an ALE(atomic layer epitaxy) method. A gas supply part(120) supplies a reaction gas for forming the thin films to the reaction chamber. A light source(160) generates light for heating the substrates to a process temperature. A plurality of beam splitters(170) split the light irradiated from the light source and guides the split light to the substrates. The light irradiated to the substrates by the beam splitters have substantially the same light energy.

Description

APPARATUS OF FORMING A LAYER FOR MANUFACTURING A SEMICONDUCTOR DEVICE}

1 is a schematic cross-sectional view illustrating a film forming apparatus for manufacturing a semiconductor according to the prior art.

2 is a schematic cross-sectional view for explaining a film forming apparatus for manufacturing a semiconductor according to the present invention.

FIG. 3 is a graph showing a change in deposition rate per cycle according to a change in process temperature for forming a TiN film using the film forming apparatus of FIG. 2.

Explanation of symbols on the main parts of the drawings

100 film forming apparatus 104 reaction chamber

110: susceptor 120: gas supply unit

122: nozzle 130: piping

132: gas supply path 140: drive unit

142: drive shaft 150: gas outlet

160: light source 170: beam splitter

W: Substrate

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film forming apparatus for semiconductor manufacturing, and more particularly, to a film forming apparatus for forming a film on a substrate by using an atomic layer epitaxy (ALE) method.

The semiconductor device includes a fab process for forming an electrical circuit on a silicon wafer used as a semiconductor substrate, a process for inspecting electrical characteristics of the semiconductor devices formed in the fab process, and the semiconductor devices each made of an epoxy resin. It is manufactured through a package assembly process for encapsulation and individualization.

The fab process includes a deposition process for forming a film on a semiconductor substrate, a chemical mechanical polishing process for planarizing the film, a photolithography process for forming a photoresist pattern on the film, and the photoresist pattern. An etching process for forming the film into a pattern having electrical characteristics, an ion implantation process for implanting specific ions into a predetermined region of the semiconductor substrate, a cleaning process for removing impurities on the semiconductor substrate, and the film or pattern Inspection process for inspecting the surface of the formed semiconductor substrate;

The deposition process is a process of forming various films on a semiconductor substrate, and includes a chemical vapor deposition (CVD) method, a physical vapor deposition (PVD) method, an atomic layer deposition (ALD) method, and the like.

In particular, in recent years, as the degree of integration of semiconductor substrates is improved, thin films are deposited using atomic layer epitaxy (ALE), which is excellent in uniformity and step-coverage in fine pattern structures such as contact holes and via holes. Research is actively underway.

The atomic layer epitaxy (ALE) method is also called cyclic CVD as one of the CVD methods, and is a technology that uses a self-limiting growth mechanism by surface saturation, and which can control the thickness of an atomic layer unit. to be.

Specifically, unlike chemical vapor deposition (CVD), in which growth is mainly caused by surface reaction of reactants injected into the reaction chamber, atomic layer epitaxy (ALE) method suppresses vapor phase reaction and thus surface saturation reaction. As the growth occurs due to a saturated surface reaction, a thin film of 1 ml (monolayer) or less is grown per cycle.

The ALE method has a lower deposition rate than the conventional CVD method, but the surface roughness of the thin film is very small, and even in large area deposition, the thickness uniformity is excellent and the process temperature is low.

The film forming apparatus described below can be used for the atomic layer epitaxy method.

1 is a cross-sectional view showing a film forming apparatus for manufacturing a semiconductor according to the prior art.

Referring to FIG. 1, the conventional film forming apparatus 10 includes a process chamber 20 in which a deposition process is performed. The susceptor 22 for loading the substrate W is provided in the processor chamber 20.

The susceptor 22 has a receiving groove 26 for receiving the substrate (W). The bottom of the receiving groove 26 is formed such that only a predetermined region of the edge of the substrate W contacts the receiving groove 26.

The driving unit 30 is connected to the susceptor 22 and provides a power for horizontally rotating the susceptor 22.

A light source 32 is provided at a lower end of the susceptor 22 to irradiate light onto the substrate W in order to increase the temperature of the substrate W in contact with the receiving groove 26.

The gas supply unit 40 supplying the deposition gas into the process chamber 20 and the gas exhaust unit 44 exhausting the gas in the process chamber 20 to the outside are provided.

As described above, the conventional film forming apparatus 10 configured to irradiate light emitted from the light source 32 onto the one substrate W has a problem in that a plurality of substrates W cannot be used in a deposition process. . This causes a problem that the productivity of the semiconductor device is lowered.

Therefore, it is necessary to improve the structure of the film forming apparatus so that the throughput can be improved by using a plurality of substrates W in the deposition process.

An object of the present invention for solving the above problems is to provide a film forming apparatus for semiconductor manufacturing having an improved structure capable of simultaneously forming a film on a plurality of substrates.

In order to achieve the above object, a film forming apparatus for manufacturing a semiconductor according to an embodiment of the present invention accommodates a plurality of substrates and uses an atomic layer epitaxy (ALE) method on the substrates. A reaction chamber for forming thin films, a gas supply for supplying a reaction gas for forming the thin films to the reaction chamber, a light source for generating light for heating the substrates to a process temperature, and irradiation from the light source And a plurality of beam splitters for splitting the light to guide the respective light onto the substrates.

Here, the lights irradiated onto the substrates by the beam splitters each have substantially the same light energy as each other.

According to one embodiment of the present invention as described above, by using the plurality of beam splitters to form a film on each of the plurality of substrates at the same time. Thus, compared with the prior art configured to irradiate light onto only one substrate, the desired film can be formed on the plurality of substrates within the same deposition process time as in the prior art, thereby improving throughput.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a schematic cross-sectional view illustrating a film forming apparatus for manufacturing a semiconductor according to the present invention.

Referring to FIG. 2, the film forming apparatus 100 according to the present exemplary embodiment includes a reaction chamber 104 for largely using an atomic layer epitaxy (ALE) method, and a reaction gas on the substrates W. FIG. A gas supply unit 120 provided to the light source, a light source 160 generating light, a plurality of beam splitters 170 for raising the temperature of the substrates W, and the reaction chamber 104. The gas discharge unit 150 for discharging the unreacted gas in the inside).

The film forming apparatus 100 is mainly used for a thin film deposition process by atomic layer epitaxy (ALE) method. However, the film forming apparatus 100 may also be used in chemical vapor deposition (CVD), atomic layer deposition (ALD), or the like.

The atomic layer epitaxy method is also called cyclic CVD as one of chemical vapor deposition methods, and uses a known self-limiting growth mechanism by surface saturation. to be.

In order to form a thin film on the substrates W in the deposition process by the atomic layer epitaxy, it is essential to provide a reaction gas to the reaction chamber 104 at a sufficient concentration.

The growth rate of the thin film by the atomic layer epitaxy method is controlled by the property of the surface of the substrate (W) rather than by the concentration or quality of the reaction gas flowing into the reaction chamber (104). In contrast, the growth rate of the thin film by the chemical vapor deposition method is mainly adjusted by controlling the inflow rate of the reaction gas colliding on the substrate (W).

The atomic layer epitaxy method has a lower deposition rate than the conventional chemical vapor deposition method, but the surface roughness of the thin film is very small, and even in a large area deposition, the thickness uniformity is excellent and the process temperature is low.

Therefore, the film forming apparatus 100 can form a thin film having a very uniform thickness even when the surface is curved by using the atomic layer epitaxy method. And a thin film requiring excellent uniformity in the formation and the large area of the protective film, the dielectric film and the diffusion barrier film.

As shown, the susceptor 110 is disposed inside the reaction chamber 104, and a plurality of semiconductor substrates W are supported in the horizontal direction on the susceptor 110.

The gas supply part 120 is positioned above the susceptor 110, and supplies a reaction gas to upper surfaces of the substrates W supported by the susceptor 110. The gas supply part 120 has a disk shape and has a space 124 for accommodating the reaction gas therein. The gas supply unit 120 and the susceptor 110 may have a shape corresponding to each other to form a thin film on the substrates W supported by the susceptor 110, respectively.

Specifically, the susceptor 110 has a disk shape corresponding to the gas supply part 120, and the substrates W are supported in the circumferential direction on the susceptor 110. An upper portion of the gas supply unit 120 is connected to a pipe 130 that functions as a passage for providing the reaction gas. The susceptor 110 fixes the semiconductor substrates W to the upper surface by using electrostatic force or vacuum pressure.

The gas supply passage 132 is formed through the pipe 130 and communicates with the space 124 located inside the gas supply unit 120. In addition, a plurality of nozzles 122 are formed to communicate radially from the center of the space 124. The gas supply passage 132 is connected to a valve to adjust the flow rate of the reaction gas, the space 124 is the reaction gas discharged through the plurality of nozzles 122 are the plurality of nozzles 122 ) To spread the same.

The nozzles 122 have the same cross-sectional area, and the spacing between each nozzle 122 gradually decreases from the center of the gas supply part 120 toward the edge. That is, the flow rate of the reaction gas gradually increases from the center of the susceptor 110 supporting the substrates W to the edge. Therefore, a thin film having a uniform thickness may be formed on the substrates W. FIG.

Each of the nozzles 122 has a form of a through hole that passes through a lower portion of the gas supply part 120 and communicates the outside of the gas supply part 120 with the space 124. In addition, each of the nozzles 122 may have a protrusion 126 extending the through hole.

A light source 160 for generating light for heating the substrates W to a process temperature is provided, and a plurality of light sources for splitting the light emitted from the light source 160 to guide the substrates W onto the substrates W, respectively. Beam splitters 170 are provided.

Specifically, the plurality of beam splitters 170 are disposed on the substrates W in the reaction chamber 104 to raise the temperature of the substrates W to a predetermined process temperature. More specifically, the beam splitters 170 are suitably disposed on the substrates W so that the light radiated from the light source 160 is irradiated onto the substrates W, respectively, and the reaction chamber 104 ) And irradiates light onto the substrates W so that the reactant gases supplied to the Cn may cause a surface saturation reaction to form the thin films. The irradiated lights raise the temperature of the substrates W to a process temperature by heating the substrates W. FIG.

In this case, the beam splitters 170 properly adjust the beam splitters 170 so that the light irradiated on the substrates W has the same light energy. This is to maintain the same temperature of the substrates W, thereby simultaneously forming the same thin film on the substrates W, respectively.

As described above, the film forming apparatus 100 according to the present embodiment raises the temperatures of the plurality of substrates W to the process temperature simultaneously using the plurality of beam splitters 170.

Accordingly, although light irradiated from a light source is conventionally irradiated onto only one substrate W, the film forming apparatus 100 according to the present exemplary embodiment may emit light irradiated from the light source 160 to the plurality of splitters 170. Are irradiated onto the plurality of substrates W, respectively.

Accordingly, since a desired film may be formed on the plurality of substrates W within the same deposition process time as in the prior art, throughput may be improved as compared with the conventional art.

Unlike the present embodiment, the temperature of the substrates W may be increased to the process temperature by using plasma without using the beam splitters 170 to increase the temperature of the substrates W to the process temperature. .

The driving unit 140 is located under the reaction chamber 104. In this case, the driving unit 140 is connected to the susceptor 110 by a driving shaft 142 and provides a driving force for rotating the susceptor 110. Although not shown, the driving unit 140 may be a motor or the like for generating a rotational force.

The gas outlet 150 is a pipe connecting the reaction chamber 104 and the vacuum pump to discharge the reaction gas supplied to the reaction chamber 104 and the inert gas and the reaction by-products generated during the deposition process. It includes a valve for opening and closing the. In addition, the gas discharge unit 150 performs a function of uniformizing the flow of the reaction gases.

Hereinafter, a method of forming a silicon oxide film on the substrates W using the film forming apparatus 100 will be described.

After fixing the plurality of substrates W on the susceptor 110, a first reaction gas including a first reaction material is supplied through the nozzle 122 of the gas supply unit 120. In this case, the first reaction material reacts with the surfaces of the upper surfaces of the substrates W and chemically adsorbs until it is saturated.

Subsequently, when the reaction between the first reactive material and the upper surface of the substrates (W) is saturated, the excess of the first reactive material on the first reactive material chemically adsorbed to the substrates (W) This is physically adsorbed.

Subsequently, a purge gas is supplied onto the substrates W to remove the physically adsorbed first reactant. Then, a second reactant gas containing a second reactant material is supplied over the substrates (W). The supplied second reactive material chemically reacts with the first reactive material layer formed on the upper surfaces of the substrates W, thereby forming a thin film of a desired material in atomic layer units. The excess second reaction gas is discharged from the reaction chamber 104 by the supply of purge gas.

The above process forms one cycle, and the cycle can be repeated to grow a thin film of a desired thickness.

In order for the deposition reaction to remain stable in the reaction chamber 104, the reaction gases must be separated from each other to prevent mixing. Therefore, each reaction gas must be injected into the reaction chamber 104 at a time difference.

Meanwhile, a plurality of gas supply paths 132 may be formed to inject the reaction gases, respectively.

FIG. 3 is a graph showing a change in deposition rate per cycle according to a change in process temperature for forming a TiN film using the film forming apparatus of FIG. 2.

In the graph, the X axis represents a change in process temperature, and the Y axis represents a change in deposition rate per cycle according to the change in the process temperature.

Referring to FIG. 3, TiN thin films were formed on the substrates W using the film forming apparatus 100 and the characteristics thereof were analyzed.

In order to deposit the TiN thin film by the atomic layer epitaxy method in the film forming apparatus 100, the TiN thin film was deposited by depositing 5000 SiO SiO ₂ insulating film on the silicon substrate W by RF sputtering.

TEMAT (tetrakis (ethylmethylamino) titanium) as a precursor used to form the TiN thin film and NH ₃ (99.9995%) were used as a reaction gas. TEMAT is a material that complements the advantages and disadvantages of tetrakis (dim ethylamino) titanium (TDMAT) and tetrakis (diethylamino) titanium (TDEAT) and has a higher equilibrium vapor pressure than TDEAT.

The TEMAT was maintained at 65 ° C. in a thermostat, where the equilibrium vapor pressure of the TEMAT was 700 mTorr. In addition, the gas supply path 132 was maintained at 65 ° C. or higher to prevent the TEMAT from condensing into the gas supply path 132. The carrier gas and the purge gas used high purity nitrogen (99.999%).

When the TiN thin film was deposited, the working pressure of the reaction chamber 104 was maintained at 1 Torr, and each reaction gas was alternately injected into the reaction chamber 104 in the order of TEMAT-N ₂ -NH ₃ -N ₂ . . The flow rate of the reaction gas provided to the reaction chamber 104 was 200 sccm for NH ₃ , 100 sccm for N ₂ for the TEMAT carrier gas, and 200 sccm for N ₂ for the purge gas.

The sequential pulse injection time was maintained at 5 seconds for TEMAT, 5 seconds for N ₂ for purge gas, and 5 seconds for NH ₃ , respectively.

Under the above process conditions, as a result of performing a deposition process by the primary layer epitaxy method using the film forming apparatus 100, the inside of the reaction chamber 104 by irradiating light onto the substrates W, respectively. In the process temperature formed in the range of 150 ~ 220 ℃ it shows a constant deposition rate of 4.5 Å / cycle regardless of the process temperature.

The result is that the TiN thin film is not deposited by vapor phase reaction by thermal decomposition of the source. It is shown by the atomic layer epitaxy (ALE) method that the surface saturation reaction takes place.

Here, the deposition rate rapidly increased at a process temperature of 230 ° C. or higher. This shows that in addition to the surface saturation reaction, a gas phase reaction by pyrolysis of the TEMAT occurred.

Conventionally configured to irradiate light onto only one substrate W by forming desired thin films on the plurality of substrates W by atomic layer epitaxy using the film forming apparatus 100 as described above. Compared to the technology, throughput can be improved at the same deposition process time as in the prior art.

According to a preferred embodiment of the present invention as described above, the plurality of beam splitters are used to irradiate light onto the plurality of substrates, respectively. The irradiated lights have the same energy and are simultaneously irradiated onto the substrates.

 Accordingly, the film forming apparatus according to the present embodiment uses one light source as in the prior art, but is configured to split the light irradiated from the light source using the plurality of beam splitters and to irradiate it onto the plurality of substrates.

Therefore, the light is not irradiated onto only one substrate as in the prior art, and the light is irradiated onto the plurality of substrates, respectively, thereby forming a desired film on the plurality of substrates at the same deposition process time as in the prior art. Can be.

Thus, the throughput according to the deposition process can be improved as compared with the prior art, and thus the productivity of the semiconductor device can be improved.

Although described above with reference to the preferred embodiment of the present invention, those skilled in the art various modifications and variations of the present invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (2)

A reaction chamber accommodating a plurality of substrates, each reaction chamber for forming thin films on the substrates using an atomic layer epitaxy (ALE) method; A gas supply unit for supplying a reaction gas for forming the thin films to the reaction chamber; A light source for generating light for heating the substrates to a process temperature; And And a plurality of beam splitters for splitting the light emitted from the light source and guiding the light onto the substrates, respectively. The film forming apparatus according to claim 1, wherein the lights irradiated onto the substrates by the beam splitters each have substantially the same light energy as each other.

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