Patent Application
20120164347
This application claims the priority of Korean Patent Application No. 10-2010-0133341 filed on Dec. 23, 2010, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a susceptor and a chemical vapor deposition (CVD) apparatus, and more particularly, to a susceptor for a CVD apparatus, and a CVD apparatus including the same, allowing for the uniform heating of a semiconductor growth substrate.
2. Description of the Related Art
Recently, a metal organic chemical vapor deposition (MOCVD) has come to prominence as one of various chemical vapor deposition (CVD) technologies according to developments in micro-LEDs and highly efficient LED outputs.
MOCVD is one of various CVD vapor phase growth methods for a compound semiconductor in which a metal compound is deposited on a semiconductor substrate through a thermal decomposition reaction in an organic metal and in which a reactive gas passes over a heated wafer generating a chemical vapor deposition of a reactive material thin film, and therefore, a number of layers may be formed on the wafer through consecutive processes.
At this time it is necessary to form a thin film having a uniform thickness across the entire surface of a wafer. Therefore, the controlling of the temperature in the heating of the wafer to have a uniformly heat throughout may be more important.
An aspect of the present invention provides a susceptor and a chemical vapor deposition (CVD) apparatus capable of uniformly heating a substrate even in the case of a bowing effect occurring in the substrate when heating the substrate mounted on the susceptor so as to grow a high quality semiconductor thereon.
According to an aspect of the present invention, there is provided a susceptor for a CVD apparatus including: a susceptor body having an upper surface opposed to a lower surface thereof and formed of a light transmitting material, the upper surface thereof having at least one pocket part formed to receive a substrate therein; and a light absorbing unit formed of a light absorbing material on the upper surface of the susceptor body.
The pocket part may include a bottom portion and a step part formed at a position spaced apart from the bottom portion in an upward direction, on which a rim of the substrate may be supported.
The step part may be formed in the susceptor body or at an end part of the light absorbing unit that is formed to extend to the pocket part.
The light transmitting material may be at least one selected from a group consisting of quartz, sapphire and a translucent ceramic.
The light absorbing material may be at least one selected from a group consisting of graphite, SiC and graphite coated with SiC.
The light absorbing material may absorb light of 400 nm to 100 μm in wavelength.
According to another aspect of the present invention, there is provided a CVD apparatus including: a chamber; a susceptor for a CVD apparatus adapted within the chamber, and including a susceptor body having an upper surface opposed to a lower surface thereof and formed of a light transmitting material, the upper surface thereof having at least one pocket part formed to receive a substrate therein, and a light absorbing unit formed of a light absorbing material on the upper surface of the susceptor body; and a heating lamp emitting light to heat the lower surface of the susceptor.
The pocket part may include a bottom portion and a step part formed at a position spaced apart from the bottom portion in an upward direction, on which a rim of the substrate may be supported.
The substrate may be provided to have the light absorbing layer bondedly combined therewith or to be formed separately thereto.
The pocket part may include a step part in which the substrate is supported, and a bottom, and the bottom of the pocket part may be spaced apart from the step part by a given interval.
The step part may be formed in the susceptor body or at an end part of the light absorbing unit that is formed to extend to the pocket part.
The light absorbing material may absorb light of 400 nm to 100 μm in wavelength.
The light transmitting material may be at least one selected from a group consisting of quartz, sapphire and a translucent ceramic.
The light absorbing material may be at least one selected from a group consisting of graphite, SiC and graphite coated with SiC.
Further comprising a light absorbing layer formed of the light absorbing material on the lower surface of the substrate, and wherein the light absorbing layer may be formed by laminating a plurality of layers of materials having different coefficients of thermal expansion.
According to another aspect of the present invention, there is provided a method of heating a substrate by using a CVD apparatus including: arranging a susceptor for a CVD apparatus including a susceptor body having an upper surface opposed to a lower surface thereof and formed of a light transmitting material, and a light absorbing unit formed of a light absorbing material on the upper surface of the susceptor body, the upper surface having at least one pocket part formed to receive the substrate therein; forming a light absorbing layer formed of a light absorbing material on a lower surface of the substrate formed of a light transmitting material; mounting the substrate having the light absorbing layer formed on the lower surface thereof, in the pocket part, and disposing the mounted substrate within a chamber of the CVD apparatus; and irradiating light to the lower surface of the susceptor body to provide heat thereto.
The substrate may be formed of at least one selected from a group consisting of quartz, sapphire and a translucent ceramic.
The substrate may be provided with the light absorbing layer deposited on or bonded to the lower surface thereof.
The light absorbing layer may be formed by laminating a plurality of layers of materials having different coefficients of thermal expansion.
According to another aspect of the present invention, there is provided a method of heating a substrate by using a CVD apparatus including: arranging a susceptor for a CVD apparatus including a susceptor body having an upper surface opposed to a lower surface thereof and formed of a light transmitting material, and a light absorbing unit formed of a light absorbing material on the upper surface of the susceptor body, the upper surface having at least one pocket part formed to receive the substrate therein; forming a light absorbing layer in the pocket; mounting the substrate on the light absorbing layer and disposing the mounted substrate within a chamber of the CVD apparatus; and irradiating light to the lower surface of the susceptor body to provide heat thereto.
The light absorbing layer may be formed by laminating a plurality of layers of materials having different coefficients of thermal expansion.
The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings such that they could be easily practiced by those having skill in the art to which the present invention pertains. However, in describing the exemplary embodiments of the present invention, detailed descriptions of well-known functions or constructions will be omitted so as not to obscure the description of the present invention with unnecessary detail.
In addition, like reference numerals denote like elements throughout the drawings.
Unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising,” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.
The substrate 11 in the left pocket part of the susceptor 10 is shown as being convex towards the susceptor 10. That is, a center of the substrate 11 may be in contact with a bottom 14 of the pocket part, and a rim of the substrate 11 may be separated from the bottom 14 of the pocket part, such that the temperature of the center of the substrate 11 may be higher than that of the rim of the substrate 11 to thereby cause an uneven substrate temperature.
The substrate 21 in the right pocket part of the susceptor 10 may be upwardly convex. In this case, a rim of the substrate 21 may be in contact with the bottom 14 of the pocket part and a center of the substrate 21 may be separated from the bottom of the pocket part, such that the temperature of the rim of the substrate 21 may be higher than that of the center of the substrate 21 to cause an uneven substrate temperature.
The susceptor body 104 may be formed of a light transmitting material and have at least one pocket part 105. The light transmitting material may be formed of at least one selected from a group of quartz, sapphire and a translucent ceramic.
The pocket part 105 may include a step part 105a on which the rim of the substrate is supported, and a bottom 105b. The step part 105a may be formed at a position spaced apart from the bottom 105b in an upward direction, on which a rim of the substrate is supported. Though described in detail below, the step part 105a may be formed at a position spaced apart from the bottom 105b in an upward direction such that, when a heated substrate is curved to be convex toward the susceptor, a space to receive the substrate is provided so as to prevent the curved substrate from being in contact with the bottom 105b.
The light absorbing unit 107 may be formed on an upper surface of the susceptor body 104 and formed of a light absorbing material so as to absorb light having passed through the susceptor body 104. The light absorbing material may be at least one selected from a group consisting of graphite, SiC and graphite coated with SiC. The light absorbing material may absorb light of 400 nm to 100 μm in wavelength.
Referring to
The substrate 101 may be provided to be separated from the first light absorbing layer 102, or provided with the first light absorbing layer 102 deposited on the lower surface thereof or provided with the first light absorbing layer 102 bonded thereto.
The substrate 101 may be formed of at least one selected from a group consisting of quartz, sapphire and a translucent ceramic. The substrate 101 may be provided with a semiconductor structure stacked thereon.
The first light absorbing layer 102 may be formed of a light absorbing material to absorb light passed through the susceptor body of the susceptor and transfer heat to the substrate 101. The light absorbing material may be at least one selected from a group consisting of graphite, SiC and graphite coated with SiC. The coefficient of thermal expansion of the first light absorbing layer 102 may be approximate to a coefficient of thermal expansion of the substrate 101, such that the first light absorbing layer 102 may be closely bonded to the substrate 101 to uniformly transfer heat to the substrate 101, even when a bowing effect occurs in the substrate 101.
With reference to
Since the substrate 101 is not yet substantially heated so as not to have the bowing effect evident, the substrate 101 may maintain an approximately planar shape. Source gas as a raw material of a semiconductor to be deposited on the substrate 101 may flow in an upper part of the substrate 101 and susceptor 100.
The heating lamp 120 may irradiate light to the lower surface of the susceptor 100 to transfer heat to the light absorbing unit 107 through the susceptor body 104. A wavelength of light emitted from the heating lamp 120 may be, for example, approximately 400 nm to 100 μm, that is, approximately 700 nm to 100 μm as the wavelength of rays within the infrared region.
With reference to
The substrate 101 in the right pocket part of the susceptor 100 in
Referring to
A light absorbing layer formed of the light absorbing material may be formed on a lower surface of the substrate that is formed of a light transmitting material, in operation 720. As an example, the light absorbing layer may be formed to be deposited on the lower surface of the substrate or to be bonded to the lower surface of the substrate.
The substrate having the light absorbing layer formed thereunder may be mounted in the pocket part and disposed in the chamber of the CVD apparatus in operation 730. That is, the substrate may be mounted in the pocket part such that the light absorbing layer may be supported on the step part of the pocket part.
Instead of forming the light absorbing layer on the lower surface of the substrate in the operation 720, a separate light absorbing layer formed separately from the substrate may be mounted in the pocket part, and thereon, the substrate may be mounted.
Subsequently, light may be irradiated to the lower surface of the susceptor body by using the heating lamp to heat the susceptor and the substrate in operation 740.
As set forth above, according to an embodiment of the present invention, an enhanced quality of semiconductor growth on the substrate may be obtained by uniformly heating the substrate even when a bowing effect occurs on the substrate in heating the substrate.
While the present invention has been shown and described in connection with the exemplary embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2010-0133341 | Dec 2010 | KR | national |
