JP2007035927A - Method of manufacturing epitaxial wafer for led - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an LED epitaxial wafer capable of improving a wafer in characteristic uniformity through its surface in a liquid phase epitaxial growth method by a process of rotating the substrate in a horizontal plane. <P>SOLUTION: The circular substrate 4 is brought into contact with a material melt liquid 6 reserved in a melt unit 5 located above or a material melt liquid 6 supplied from above as the substrate 4 is rotated in a horizontal plane. Accordingly, a target compound semiconductor layer such as an AlGaAs layer, a GaP layer, a GaAsP layer or the like, is grown in a liquid phase. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an LED (light emitting diode) in which a target compound semiconductor layer is grown in a liquid phase by bringing a substrate into contact with a raw material melt stored in an upper melt portion or a raw material melt supplied from above. The present invention relates to an epitaxial wafer manufacturing method.

  Currently, epitaxial wafers for general-purpose LEDs are grown with an epitaxial layer as a constituent element thereof in a liquid phase.

  FIG. 3 shows an example of a conventional liquid phase growth apparatus. Of the upper jig 11 and the lower jig 12 that are relatively slidably overlapped, the movable lower jig 12 is provided with a substrate set portion 13 formed of a rectangular recess, and the substrate set portion 13 has a rectangular substrate 14. Is placed so that the upper surface thereof is parallel to the sliding contact surfaces of the upper jig and the lower jig, and the melt portion 15 for storing the raw material melt 16 is formed in the fixed upper jig 11. Then, the raw material melt 16 stored in the melt part 15 of the upper jig is brought into contact with the rectangular substrate 14 arranged in the substrate set part 13 of the lower jig, and a target compound semiconductor layer is grown.

  That is, after the rectangular substrate 14 is set on the lower jig 12 and the raw material melt (melt) 16 heated to a high temperature is brought into contact with the rectangular substrate 14, the temperature of the raw material melt 16 is lowered to solidify the liquid phase. Using this, epitaxial growth is performed to manufacture an LED epitaxial wafer.

In addition, a liquid phase growth apparatus (for example, refer to Patent Document 1) in which a substrate is vertically arranged and rotated so that the substrate is changed upside down during growth, or silicon is applied to tin from above on a wafer rotating in a horizontal plane. A liquid phase growth apparatus that supplies a dissolved solution (for example, see Patent Document 2) is also known.
JP 2001-163698 A Japanese Patent No. 2574922

  However, in the conventional epitaxial wafer manufacturing method using the apparatus shown in FIG. 3, the rectangular substrate 14 is fixed to the lower jig 12 and does not move during liquid phase growth. On the other hand, when the epitaxial layer grows on the rectangular substrate 14, the raw material melt 16 having a non-uniform temperature distribution and constituent element ratio is in contact with the rectangular substrate 14. For this reason, conventionally, various characteristics (mixed crystal ratio, carrier concentration, thickness) of the grown epitaxial layer are not uniform, and as a result, various characteristics (luminance, wavelength, operating voltage) of the epitaxial wafer that has been grown. The uniformity inside was also poor.

  As described above, in the conventional epitaxial growth for LEDs using the liquid phase, there is a problem that the uniformity of characteristics (luminance, wavelength, operating voltage) in the wafer surface is poor. When the uniformity of the characteristics in the wafer surface is deteriorated, the characteristics of the semiconductor elements using the same also vary, and as a result, the manufacturing yield of the LED elements decreases.

  Accordingly, an object of the present invention is to provide an LED epitaxial wafer manufacturing method that solves the above-described problems and improves the uniformity of the characteristics in the wafer plane in liquid phase epitaxial growth by rotating the substrate in a horizontal plane. It is in.

  Patent Documents 1 and 2 do not rotate the substrate in a horizontal plane, and belong to a technique different from the present invention.

  In order to achieve the above object, the present invention is configured as follows.

  The manufacturing method of the epitaxial wafer for LED which concerns on invention of Claim 1 is made to contact the raw material melt stored in the upper melt part, or the raw material melt supplied from the upper direction, rotating a circular substrate within a horizontal surface. Thus, the target compound semiconductor layer is grown in a liquid phase.

  According to a second aspect of the present invention, there is provided an LED epitaxial wafer manufacturing method comprising: storing a circular substrate in a substrate set portion of a lower jig out of an upper jig and a lower jig that are slidably stacked. The target compound semiconductor layer is grown in a liquid phase by contacting the raw material melt stored in the melt part of the upper jig while rotating in a horizontal plane together with the substrate set part.

  According to a third aspect of the present invention, in the method for manufacturing an epitaxial wafer for an LED according to the first or second aspect, any one of an AlGaAs layer, a GaP layer, or a GaAsP layer is used as a target compound semiconductor layer while rotating a circular substrate. It is characterized by growing in phases.

  According to the present invention, the following excellent effects can be obtained.

  Claim 1 specifies the form of contact with the raw material melt stored in the upper melt portion or the raw material melt supplied from above, and Claim 2 is a superior slidable overlay. It has a tool and a lower jig, a circular substrate is stored in the substrate set part of the lower jig, and the upper jig is provided with a melt part, but according to the present invention, in any form However, since the circular substrate is rotated in a horizontal plane and brought into contact with the raw material melt, the temperature distribution of the raw material melt in contact with the circular substrate and the ratio of the constituent elements are made constant so that various characteristics of the growing epitaxial layer are uniform. can do. For example, the in-plane distribution of wavelength and luminance can be suppressed to 3% or less. Further, by making the temperature distribution of the raw material melt in contact and the ratio of the constituent elements uniform, the in-plane uniformity including the wafer peripheral portion is improved. As a result, there is an effect of improving the acquisition yield of the LED elements and increasing the usable area.

  Hereinafter, the present invention will be described based on the illustrated embodiments.

  In FIG. 1, the outline | summary of the liquid phase growth apparatus to which the manufacturing method of the epitaxial wafer for LED is applied is shown.

  This liquid phase growth apparatus has an upper jig 1 and a lower jig 2 that are slidably overlapped with each other. Here, the lower jig 2 is fixed, and the other upper jig 1 is movable and can reciprocate linearly in a direction perpendicular to the paper surface of FIG.

  Of the upper jig 1 and the lower jig 2, the lower jig 2 is provided with a substrate setting portion 3 made of a holder having a circular recess, and the substrate setting portion 3 can be rotated by a rotation mechanism (not shown). is doing. Unlike the conventional case of FIG. 3, the shape of the concave portion of the substrate set portion 3 is circular as viewed from above. In the holder substrate setting portion 3, a circular substrate 4 is accommodated and disposed so that the upper surface is parallel to the sliding contact surfaces of the upper jig 1 and the lower jig 2. Therefore, when the substrate setting unit 3 of the holder is rotated by the rotation mechanism, the circular substrate 4 is also rotated together with the substrate setting unit 3 in the horizontal plane.

  On the other hand, the upper jig 1 is formed with a melt portion 5 for storing a crystal raw material melt 6.

  The raw material melt 6 stored in the melt part 5 of the upper jig 1 is placed in the substrate set part 3 of the lower jig 2 in the electric furnace heated to a certain temperature. Contact. Here, since the circular substrate 4 is rotated in one direction in the horizontal plane as shown by an arrow 7 in FIG. 2, a target compound semiconductor layer is grown by contacting the circular substrate 4 in rotation. To do. That is, after bringing the raw material melt 6 into contact with the circular substrate 4, the temperature of the raw material melt 6 is lowered and the liquid phase is solidified to perform epitaxial growth to manufacture an LED epitaxial wafer.

  In this way, the circular substrate 4 is rotated by a jig equipped with a mechanism capable of rotating the substrate setting portion 3, and the temperature distribution of the raw material melt 6 contacting the circular substrate 4 and the ratio of the constituent elements are made constant to grow. Make various characteristics of the epitaxial layer uniform.

  The compound semiconductor layer grown while rotating the circular substrate 4 is an AlGaAs layer, a GaP layer, a GaAsP layer, or the like.

  In the above-described embodiment, the upper jig and the lower jig that are slidably overlapped with each other and the circular substrate is stored in the substrate set portion of the lower jig have been described. Any form can be applied as long as it can be rotated at the same time. In addition, the present invention can be applied to all applications in which in-plane uniformity is required in the growth of LED epitaxial wafers using the liquid phase growth method.

It is the cross-sectional schematic of the liquid phase growth apparatus which implemented the manufacturing method of the epitaxial wafer for LED of this invention. It is the schematic which looked at the lower jig | tool of the liquid phase growth apparatus of FIG. 1 from the top. 1 is a schematic cross-sectional view of a conventional liquid phase growth apparatus.

Explanation of symbols

1 Upper jig 2 Lower jig 3 Substrate setting part 4 Circular substrate 5 Melt part 6 Raw material melt

Claims (3)

  A target compound semiconductor layer is grown in a liquid phase by contacting a raw material melt stored in an upper melt portion or a raw material melt supplied from above while rotating a circular substrate in a horizontal plane. The manufacturing method of the epitaxial wafer for LED characterized by these.   Among the upper and lower jigs that are relatively slidably stacked, the circular substrate is stored in the substrate set part of the lower jig and rotated in the horizontal plane together with the substrate set part, while the upper jig melts. A method for producing an epitaxial wafer for LED, wherein a target compound semiconductor layer is grown in a liquid phase by contacting with a raw material melt stored in a part.   3. The method for producing an epitaxial wafer for LED according to claim 1, wherein any one of an AlGaAs layer, a GaP layer and a GaAsP layer is grown in a liquid phase as a target compound semiconductor layer while rotating a circular substrate. The manufacturing method of the epitaxial wafer for LED.

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