JPS6321284A - Liquid phase epitaxy - Google Patents

Abstract

PURPOSE:To obtain a homogeneous growth layer in a short time by providing a sliding soln. reservoir on a slider housing a substrate, charging a growth soln. consisting of a solvent and solute in the soln. reservoir, and reciprocating the slider to dissolve the solute in a short time. CONSTITUTION:A sliding lid 4 and plural sliding soln. reservoirs 5 for storing growth solns. 6 are provided on the slider 1 housing the substrate 2 of InP, etc. A solvent (e.g., In) and a solute (e.g., InAs and GaAs) for preparing the growth soln. 6 are charged in each soln. reservoir 5, the reservoir is heated to a temp. above the saturation temp. of the solute, the soln. reservoir 5 is reciprocated through a supporting rod 9 to uniformly dissolve the solute in the solvent, and the uniform growth soln. 6 is prepared. The growth soln. 6 is then cooled and supercooled, the slider 1 is slid through a supporting rod 7, the substrate 2 is successively positioned under each soln. reservoir 5, and epitaxial growth is carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a liquid phase epitaxial growth method used in the production of optical devices such as semiconductor lasers and light receiving elements in the field of optoelectronics.

Conventional technology 2: Recently, the field of optoelectronics has made remarkable progress.
As the practical use of optical fiber communication systems progresses, optical devices such as semiconductor lasers have become increasingly important. Liquid phase epitaxial growth has traditionally been the most common crystal growth method for creating optical devices, and molecular beam epitaxy (MBE) and metal-organic vapor phase epitaxy (M
Although new growth technologies such as OVPE (OVPE) are on the verge of being put into practical use, liquid phase epitaxial growth still occupies the mainstream. Conventionally, this liquid phase epitaxial growth is
"Hikari Tsushin...Ndobunoku" Edited by Hisayoshi Yanai Published by Asakura Shoten
P143-145'' is known.

The conventional liquid phase epitaxial growth method will be explained below with reference to FIG. It is a support rod. In such a configuration, first, each growth solution 34 placed in the solution reservoir 33 is heated to a temperature equal to or higher than the saturation temperature of the solute, and maintained at a constant temperature up to 3 vanes at which the solute is uniformly dissolved. Subsequently, the temperature is gradually lowered to bring the growth solution into a supercooled state, and the slider 31 is slid by the slider support rod 35 so that the substrate 32 is below the growth solution. Growth is performed by placing the substrate 32 under each growth solution 34 at a predetermined temperature for a predetermined time. Although the time required to uniformly dissolve the growth solution depends on the temperature, it is usually about one hour in order to obtain a uniform composition, film thickness, etc. of the growth layer.

Problems to be Solved by the Invention In liquid phase epitaxial growth, which has the above-mentioned configuration, the growth solution is uniformly dissolved by keeping it at a temperature above the saturation temperature of the solute for a certain period of time. occupies a large proportion of the growth time (usually about 5 to 15 minutes) in the series of steps of liquid phase epitaxial growth. This is because the dissolution time of the growth solution, which accounts for a large proportion of the time compared to the net growth time in a series of steps, can be reduced without deteriorating the uniformity of the composition and film thickness of the growth layer. It is an object of the present invention to provide a liquid phase epitaxial growth method that allows for shortening the process.

Means for Solving the Problems The present invention provides a method for dissolving a growth solution in liquid phase epitaxial growth using a boat equipped with a slider for storing a substrate and a solution reservoir for storing a growth solution that can be slid relative to the slider. At this time, the above object is achieved by increasing the convection of the growth solution by sliding the solution reservoir containing the growth solution back and forth on a slider for a certain period of time.

Effects of the present invention With the above structure, the convection of the growth solution is increased, so that the growth solution can be uniformly dissolved in a short time.

Embodiment FIG. 1 shows InP/InGa in an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view of a boat used in AsP-based liquid phase epitaxial growth. 1 is a slider, 5 pages 2 is an InP substrate, 3 is an InP cover, 4 is a lid, 5 is a solution reservoir, 6 is a growth solution, 7 is a slider support rod, 8 is a lid support rod, 9 is a solution reservoir support rod . The slider 1, the lid 4, and the solution reservoir 5 can be slid relative to each other, and can be fixed or slid by a slider support rod 7, a lid support rod 8, and a solution reservoir support rod 9, respectively. In the growth of the InP/InGaAsP system, the vapor pressure of P atoms is high, so P atoms easily escape during temperature rise.
A cover 3 is placed to protect the surface of the InP substrate 2. The lid 4 is for preventing the substrate 2 and the InP cover 3 from falling. The solution reservoir 5 contains I using In as a solvent.
nP growth solution (In + InP) or InGaAsP
Growth solution (In + InP + InAs + GaA
s) 6 is stored. In such a configuration, the temperature is first raised to dissolve each growth solution 6. Once the temperature reaches the saturation temperature of the solute or higher, conventionally the temperature is kept at a constant temperature and waits for it to dissolve uniformly, but at this point the slider 1 and lid 4 are fixed and the solution 6 and the beno reservoir 5 are supported by the solution reservoir. It is slid back and forth for a certain period of time as shown by the arrow in the figure via the rod 9. As a result, each growth solution 6 is uniformly dissolved in a shorter time than conventionally.

Next, the temperature is lowered and each growth solution 6 is supercooled, and when it reaches a predetermined temperature, the lid 4 and solution reservoir 6 are fixed, and the slider 1 is slid through the slider support rod 7 to remove the InP substrate 2. Growth is performed by sequentially positioning under each growth solution. When the saturation temperature of the growth solution 6 is 660°C,
At a melting temperature of 670°C, it conventionally required a melting time of 60 minutes or more to obtain a grown layer with a variation in film thickness within 10 parts, but in this example, a grown layer with a variation in film thickness of 10 parts or less could be obtained in about 20 minutes. It was done.

Figure 2 shows the melting temperature Ts at which the film thickness variation is within 10% when InP is grown using the method based on this example.
This figure shows the relationship between the dissolution time t8 and the dissolution time t8. The saturation temperature of the growth solution is (Ts 20) °C, and the growth temperature is (TsL2)
5) ℃. As can be seen from FIG. 2, the method according to the present invention can shorten the dissolution time by 20 to 40 minutes compared to the conventional method.

Page 7 Note that the same degree of shortening was also possible in the growth of InGaAsP quaternary mixed crystal without major changes in composition.

Effects of the Invention As described above, the present invention increases the convection of the growth solution by sliding the solution reservoir back and forth when dissolving the growth solution, thereby making it possible to uniformly dissolve the growth solution in a shorter time than before, thereby improving the composition of the growth layer. It is possible to shorten the dissolution time and therefore the time of a series of growth steps without deteriorating the film thickness uniformity.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of a boat used in an embodiment of the present invention, and FIG. 2 shows a variation in the thickness of the InP growth layer of 10
Relationship diagram between the dissolution temperature and dissolution time of the growth solution within %,
FIG. 3 is a schematic cross-sectional view of a boat used in conventional liquid phase epitaxial growth. 1.31...Slider, 2.32...
・Substrate, 5.35...Solution reservoir, 6,34...
...growth solution.

Claims (1)

[Claims] a slider for storing a substrate, a lid for protecting the substrate that is on the slider and is slidable relative to the slider, and a lid that is placed on the slider and slidable relative to the slider separately from the lid. When dissolving the growth solution by keeping it at a temperature equal to or higher than the saturation temperature of the solute using a boat equipped with a solution reservoir containing a possible growth solution, the solution reservoir containing the growth solution is slid back and forth on the slider. A liquid phase epitaxial growth method characterized by uniformizing the growth solution using