This application claims the benefit of Korean Patent Application No. 10-2010-0056691, filed on Jun. 15, 2010, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field
The present disclosure relates to susceptors and chemical vapor deposition (CVD) apparatuses including the same.
2. Description of the Related Art
In general, chemical vapor deposition (CVD) apparatuses are apparatuses for forming thin films on deposition targets (generally including substrates such as semiconductor wafers) by using chemical reaction. A CVD apparatus injects a high-pressure reaction gas into a vacuum chamber to grow a film of the reaction gas on a heated substrate in the chamber.
Currently, due to the development of micro semiconductor devices and highly efficient light emitting diodes (LEDs) having large outputs, a CVD method such as a metal organic chemical vapor deposition (MOCVD) method is attracting people. As chambers and susceptors are getting larger to simultaneously perform deposition on a plurality of deposition targets, a technology of uniformly forming a thin film on a plurality of deposition targets has become a core technology. In this case, deposition targets are disposed on satellite disks and the satellite disks are individually accommodated in a plurality of pockets formed in a susceptor. In order to uniformly grow a thin film on the deposition targets, the susceptor itself rotates and the satellite disks on which the deposition targets are disposed also rotate.
Provided are susceptors having improved structures to increase durability, and chemical vapor deposition (CVD) apparatuses including the same.
Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.
According to an aspect of the present invention, a susceptor for a chemical vapor deposition (CVD) apparatus has a shape of a disk with a hollow and includes a plurality of pockets formed in an upper surface of the susceptor to accommodate deposition targets; and susceptor channels formed in the susceptor to supply a flowing gas to the plurality of pockets, wherein inlets of the susceptor channels are formed in a sidewall of the hollow.
In this case, the susceptor channels may linearly extend from the inlets to portions below the pockets and then be bent from the portions below the pockets to outlets formed in the pockets.
According to another aspect of the present invention, a susceptor for a chemical vapor deposition (CVD) apparatus has a shape of a disk with a hollow and includes a plurality of pockets formed in an upper surface of the susceptor to accommodate deposition targets; and susceptor channels formed in the susceptor to supply a flowing gas to the plurality of pockets, wherein inlets of the susceptor channels are formed in a lower surface of the susceptor, and wherein a reinforcement unit is formed on the upper surface of the susceptor to correspond to the inlets of the susceptor channels.
In this case, the inlets of the susceptor channels may be formed along a circle around a center of the susceptor, and the reinforcement unit may protrude from a circular region on the upper surface of the susceptor to correspond to the inlets of the susceptor channels.
The reinforcement unit may protrude from and be integrally formed with the susceptor.
The plurality of pockets may be spaced apart from each other, and an edge along a circumference of each of the plurality of pockets may be continuous.
The plurality of pockets may overlap each other, an edge along a circumference of each of the plurality of pockets may be discontinuous to have discontinuous portions, and at least the discontinuous portions may have round cross sections. In this case, the round cross sections of the discontinuous portions may have a curvature radius of 0.7 mm to 1.3 mm.
The susceptor may be hard-coated. In this case, the susceptor is formed by coating silicon carbide (SiC) on graphite.
According to another aspect of the present invention, a chemical vapor deposition (CVD) apparatus includes a susceptor having a shape of a disk with a hollow; and a supporting unit for supporting the susceptor and injecting a flowing gas into the susceptor to rotate deposition targets, wherein the susceptor includes a plurality of pockets formed in an upper surface of the susceptor to accommodate the deposition targets; and susceptor channels formed in the susceptor to supply the flowing gas to the plurality of pockets, and wherein inlets of the susceptor channels are formed in a sidewall of the hollow such that the supporting unit injects the flowing gas from the sidewall of the hollow of the susceptor.
The susceptor channels may linearly extend from the inlets to portions below the pockets and then be bent from the portions below the pockets to outlets formed in the pockets.
According to another aspect of the present invention, a chemical vapor deposition (CVD) apparatus includes a susceptor having a shape of a disk with a hollow; and a supporting unit for supporting the susceptor and injecting a flowing gas into the susceptor to rotate deposition targets, wherein the susceptor includes a plurality of pockets formed in an upper surface of the susceptor to accommodate the deposition targets; and susceptor channels formed in the susceptor to supply the flowing gas to the plurality of pockets, wherein inlets of the susceptor channels are formed in a lower surface of the susceptor such that the supporting unit injects the flowing gas from the lower surface of the susceptor, and wherein a reinforcement unit is formed on the upper surface of the susceptor to correspond to the inlets of the susceptor channels.
The inlets of the susceptor channels may be formed along a circle around a center of the susceptor, and the reinforcement unit may protrude from a circular region on the upper surface of the susceptor to correspond to the inlets of the susceptor channels.
These and/or other aspects will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects of the present description.
Referring to
The susceptor 110 may have a shape of a disk with a hollow 110a. A plurality of the pockets 111 are formed in an upper surface of the susceptor 110. As illustrated in
Deposition targets such as wafers are disposed on the satellite disks 120. A rim (not shown) may be formed along a circumference of each of the satellite disks 120 so as to prevent movement of the deposition targets.
Susceptor channels 115 for supplying the flowing gas G1 to the pockets 111 are formed in the susceptor 110. Inlets 115a of the susceptor channels 115 are formed in a sidewall of the hollow 110a of the susceptor 110. Meanwhile, the outlets 115b of the susceptor channels 115 are formed in the bottom surfaces of the pockets 111. The number of susceptor channels 115 may correspond to the number of pockets 111. One susceptor channel 115 may be divided to a plurality of outlets 115b. Since the inlets 115a of the susceptor channels 115 are formed in the sidewall of the hollow 110a of the susceptor 110, the susceptor channels 115 linearly extend from the inlets 115a to portions below the pockets 111 and then are bent from the portions below the pockets 111 to the outlets 115b formed in the pockets 111.
Meanwhile, a material for forming the susceptor 110 may vary according to a method of heating the deposition targets disposed on the satellite disks 120. If an induction heating method is used, the susceptor 110 may be formed of a material that may be heated by using the induction heating method. For example, the susceptor 110 may be formed of graphite. The susceptor 110 may be hard-coated to increase the durability of the susceptor 110. For example, the susceptor 110 may be formed by coating silicon carbide (SiC) on graphite. Since the susceptor 110 is self-heated to heat the deposition targets, the susceptor 110 may be damaged by thermal impact. However, the damage of the susceptor 110 may be reduced by improving the structure of the susceptor 110 as described below.
The supporting unit for supporting the susceptor 110 includes a supporting disk 130 disposed at a lower portion of the susceptor 110, an upper coupling plate 140 disposed at an upper portion of the susceptor 110, and a supporting tube 150 coupled to the supporting disk 130 to function as a rotation shaft. The upper coupling plate 140 and the supporting disk 130 may be coupled to each other by using a well-known coupling means, and the susceptor 110 fitted between the upper coupling plate 140 and the supporting disk 130 is fixed on the supporting disk 130. The supporting disk 130 is coupled to the supporting tube 150 and the supporting tube 150 is connected to a flowing gas injection unit 160.
Meanwhile, supporting disk channels 135 through which the flowing gas G1 flows are formed in the supporting disk 130. The supporting disk channels 135 are connected to supporting tube channels 155 of the supporting tube 150, and outlets 135a of the supporting disk channels 135 are formed in an outer circumference of the supporting disk 130. If a portion of the supporting disk 130 is inserted into the hollow 110a of the susceptor 110, the outlets 135a of the supporting disk channels 135 face the inlets 115a of the susceptor channels 115. Although the outlets 135a of the disk channels 135 one-to-one correspond to the inlets 115a of the susceptor channels 115 in
The supporting tube 150 may be a hollow shaft or a rod. The supporting tube channels 155 are formed in the supporting tube 150 and are connected to injection unit channels 165 of the flowing gas injection unit 160.
The flowing gas injection unit 160 is connected to flowing gas supply lines 169 to inject the flowing gas G1 into the supporting tube channels 155 of the supporting tube 150, and transfers rotatory power of a driving motor 170 to the supporting tube 150. In this case, in order to maintain the chamber 190 to be sealed, ferrofluid sealing may be performed on a gap between the chamber 190 and a rotation part of the flowing gas injection unit 160.
Meanwhile, the flowing gas G1 may be, for example, nitrogen, and rotation of the satellite disks 120 may be actively controlled by adjusting a flow rate of the flowing gas G1 supplied to the flowing gas supply lines 169. Furthermore, rotation of the satellite disks 120 may be differently controlled by adjusting the flow rate of the flowing gas G1 supplied to each or some of the pockets 111.
The heater 175 heats the susceptor 110 to a predetermined temperature. The heater 175 may heat the susceptor 110 to a temperature equal to or greater than several hundreds to 1000° C. For example, in order to grow a gallium nitride (GaN)-based layer, the heater 175 may heat the susceptor 110 to about 700 to 1300° C. The heater 175 may be coil to which a high-frequency current is applied and, in this case, the susceptor 110 may be heated by using an induction heating method. Alternatively, the heater 175 may be a conducting wire that generates resistance-heat.
The reaction gas injection unit 180 is a device for supplying the reaction gas G2 including a carrier gas and a source gas to be deposited on the deposition targets. The nozzle 185 of the reaction gas injection unit 180 is exposed in the chamber 190 and the reaction gas G2 is discharged through nozzle holes 185a of the nozzle 185.
The deposition targets are maintained at a high temperature due to the highly heated susceptor 110, and chemical deposition reaction occurs on upper surfaces of the deposition targets which contact the reaction gas G2. Due to the chemical deposition reaction, a predetermined material such as a GaN-based compound crystal-grows on the deposition targets such as wafers.
The chamber 190 accommodates the susceptor 110 and the nozzle 185 of the reaction gas injection unit 180, and may be sealed in a deposition process and may be open to replace the deposition targets.
The gas discharging unit 195 discharges the flowing gas G1 and the reaction gas G2 filled in the chamber 190.
Improvements of the CVD apparatus 100 will now be described by comparing it with a CVD apparatus according to a comparative example.
On the other hand, in the susceptor 110 illustrated in
As described above, in comparison to the susceptor 210, the life of the susceptor 110 may be greatly extended by suppressing breakages near the inlets 115a, and a manufacturing cost of the CVD apparatus 100 including the susceptor 110 may be reduced.
Furthermore, in the susceptor 110, the pockets 111 are equally spaced apart from each other as illustrated in
In a general commercialized susceptor, a plurality of pockets overlap each other as illustrated in
Unlike the general commercialized susceptor, in the susceptor 110 illustrated in
However, the CVD apparatus 100 is not limited to a structure in which the pockets 111 are spaced apart from each other as described above.
Referring to
Referring to
In the susceptor 410, inlets 415a of susceptor channels 415 are formed in a lower surface of the susceptor 410. As such, the susceptor channels 415 proceed upward from the lower surface of the susceptor 410, are bent in horizontal directions, and then are bent upward from portions below pockets 411. As such, outlets 435a of supporting disk channels 435 of a supporting disk 430, which are connected to the inlets 415a of the susceptor channels 415, are formed in an upper surface of the supporting disk 430.
If the susceptor channels 415 are bent near the inlets 415a of the susceptor channels 415 as described above, the possibility of damaging the susceptor 410 may be increased. As such, the susceptor 410 includes a reinforcement unit 417 to reduce the possibility of damaging the susceptor 410. The reinforcement unit 417 is formed on an upper surface of the susceptor 410 to correspond to the inlets 415a of the susceptor channels 415. The inlets 415a of the susceptor channels 415 may be formed along a circle around the center of the susceptor 410, and the reinforcement unit 417 may protrude from a circular region on the upper surface of the susceptor 410 to correspond to the inlets 415a of the susceptor channels 415. The reinforcement unit 417 may protrude from and be integrally formed with the susceptor 410. In some cases, the reinforcement unit 417 may be separately formed and then bonded onto the susceptor 410. Furthermore, a plurality of reinforcement units 417 may be formed to individually correspond to the inlets 415a of the susceptor channels 415. In this case, the height of the reinforcement unit 417 may be designed not to disturb the flow of the reaction gas G2 released from the nozzle 185 of the reaction gas injection unit 180.
The susceptor 410 may be formed by coating SiC on a graphite layer. In this case, the reinforcement unit 417 may protrude from the graphite layer and SiC may be coated on the graphite layer from which the reinforcement unit 417 protrudes. In some cases, a planarization layer may be further formed to planarize the upper surface of the susceptor 410. If the susceptor 410 is formed by coating SiC on the graphite layer, the upper surface of the susceptor 410 may be planarized by using a chemical mechanical polishing (CMP) method, a lapping method, or the like.
Except for the susceptor 410 and channel structures of the supporting unit for supporting the susceptor 410, the CVD apparatus 400 is substantially the same as the CVD apparatus 100 illustrated in
As described above, according to one or more of the above embodiments of the present invention, a susceptor and a chemical vapor deposition (CVD) apparatus including the same have the following effects.
First, breakages of the susceptor near inlets of a flowing gas may be prevented by improving the structure of gas channels of the susceptor.
Second, breakages of the susceptor near pockets may be prevented by improving the structure of circumferences of the pockets.
Third, a long life of a susceptor may be ensured, and productivity and deposition quality may be improved.
It should be understood that the exemplary embodiments described therein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments.
Number | Date | Country | Kind |
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10-2010-0056691 | Jun 2010 | KR | national |