JPS61267388A - Manufacture of semiconductor laser resonator - Google Patents

Abstract

PURPOSE:To improve mass productivity by forming semiconductor multilayer films which control reflectance before a semiconductor laser wafer is divided into bars. CONSTITUTION:Stripe patterns made of SiO2 are formed as etching-resistant films 2 on a double hetero structure semiconductor wafer 1 whose activation layer 10 is made of InGaAsP and cladding layer 20 is made of InP. The wafer 1 is then inserted into a reaction tube and etched with a mixture gas of hydrochloric acid with H2. The supply of the etching gas is discontinued and a mixture gas of AsH3 with PH3 is supplied and then a mixture of trimethyl indium (TMI) and PH3 and a mixture of TMI, trimethyl gallium, PH3 and AsH3 are alternately introduced to make high-resistance multilayer films 100 on the sides of steps. After that, electrodes are formed and the wafer 1 is cut into elements by cleaving, so that semiconductor lasers can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a resonator for a semiconductor laser.

[Conventional technology]

In a normal semiconductor radar made by cleavage, the light output from both cleavage planes is equal. 1 for communication phase semiconductor lasers
One output light is input into the fiber, and the other output light is used as optical power monitoring light. In this case, in order to increase the optical output of the emitted light input to the fiber, the cleavage plane on the optical power monitor side is coated with a dielectric multilayer or Au to increase the reflectance, and the reflection of the resonator surface is Rate control is important for semiconductor lasers.

FIG. 3 shows a conventional method for manufacturing a semiconductor radar in which the reflectance of the end face is changed. In the figure, the conventional production method is performed as follows. That is, the semiconductor laser wafer 1 shown in FIG. 3(a) is cleaved to form a semiconductor laser wafer par 90 having a width of approximately 200 to 360 #m as shown in FIG. 3(b). Next, as shown in FIG. 3(c), a dielectric multilayer film 200 is formed on the end face of the bar 90 using a method such as sputtering or plasma CVD, and the refractive index of the end face is changed. Create a resonator surface. In the figure, 10 is an active layer, and 20 is a cladding layer.

[Problem that the invention seeks to solve]

However, when using this manufacturing method, ゛ becomes a semiconductor □
- The method is not suitable for mass production because the dielectric multilayer film 200 is formed on the end faces of the laser wafer after dividing the laser wafer into parts each having a width of 200 to 300 μm.

In particular, semiconductor laser wafers have a very small diameter and are difficult to handle, requiring each wafer to be set in a device one by one and a dielectric multilayer film applied thereto, and each process must be performed separately.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a semiconductor laser resonator with controlled reflectance that can be mass-produced and eliminates the above-mentioned problems.

[Means for solving problems]

In the present invention, a semiconductor laser wafer having an etching gloss pattern such as an etching-resistant film on its surface is brought into contact with an etching gas such as hydrochloric acid gas + )iBr l PCZ3 r AsCl2 in a reaction tube, and the semiconductor laser wafer is coated with the etching pattern. A step of etching the semiconductor laser wafer in the non-etched portion to form a step on the semiconductor laser wafer, a step of removing the etched gas from the reaction tube, and supplying the semiconductor raw material gas 1-1 The step formed on the semiconductor laser wafer This method of manufacturing a resonator of a semiconductor laser is characterized in that the steps of forming a semiconductor multilayer film on the side surface of a step are sequentially performed.

[For production]

FIGS. 1 and 2 illustrate a method for forming a resonator surface of a semiconductor laser according to the present invention. An etched glossy turn made of an etching-resistant coating 2 is formed on a semiconductor laser wafer 1 shown in FIG. 1(a).

This is inserted into a reaction tube 6o as shown in FIG. 2, set on a susceptor 50, and an etching gas such as hydrochloric acid is supplied to form an etching-resistant coating 2 as shown in FIG. 1(b). The uncoated portion of the semiconductor crystal is etched. 70 #iRF coil. The stepped side surface formed by this becomes a resonator. The introduction of etching gas into the edge reaction tube 60 is stopped and the remaining etching gas is removed. Next, a semiconductor raw material gas is supplied, and a semiconductor multilayer film 100 is formed on the side surface of the step as shown in FIG. 1(c).
Changes the reflectance of the side surface of the step. By cleaving the ridge at a convex portion and a concave portion, a semiconductor laser is obtained in which the reflecting surface having the cleaved plane and the semiconductor multilayer film 100 serves as a resonator. In the figure, 10 is an active layer and a 20Fi cladding layer.

〔Effect of the invention〕

The method for forming the resonator surface of a semiconductor laser according to the present invention is different from conventional methods.Since a semiconductor multilayer film is formed to control the reflectance before separating the semiconductor laser wafer into parts, it has excellent productivity in one process. It is easy to handle as it can be handled in the same state, and furthermore, the steps shown in FIGS. In other words, it is possible to obtain a high-quality semiconductor laser in which the reflectance of the resonator surface is controlled.

〔Example〕

This will be explained below using examples.

A 1.5 μm oscillation wave is used as the semiconductor laser wafer 1.
A double heterostructure semiconductor laser wafer was used in which the long active layer 10 was made of InGaAsP and the cladding layer 20 was made of InP. On top of that, there will be an etching-resistant coating 2.
600 μm wide striped arm turn (
A stripe-to-stripe interval of 200 μm) was formed. A semiconductor laser wafer having an etching pattern of the etching-resistant coating 2 is inserted into a reaction tube 60 as shown in FIG. 2, a mixed gas of hydrochloric acid gas and H2 is supplied, and an RF coil A-70 Etching was performed by heating to 800°C.

The etching depth was 10 μm. Thereafter, the hydrochloric acid gas was stopped, and a mixed gas of A m H5, PH3, and H2 was supplied to remove the hydrochloric acid gas in the reaction tube 60 and lower the temperature to 650°C. After that, trimethyl gallium (TMI) and PH3, trimethyl gallium (TMI)
) and trimethyl gallium (TMG) and PH5 and A m
H5 is flowed alternately, InP with a thickness of 1200X and InP with a thickness of 10X.
A 12-layer high-resistance multilayer film of InGaAaP (1.3 μm composition) of 0.00 μm was grown. Thereafter, electrodes were formed and the element was cut out by cleavage to obtain a semiconductor laser. The optical output from a semiconductor laser is compared with the output from a laser whose cleavage planes are on both end faces cut from the same laser wafer.In the laser manufactured by the method of the present invention, the output at the cleavage plane is increased, and the output from the cleavage plane is increased. It was observed that the optical output from the end face with the oscillation threshold decreased as well as the optical output from the end face.

[Brief explanation of drawings]

FIGS. 1(a) to (c) are diagrams showing the method of manufacturing a resonator surface of a semiconductor laser according to the present invention in the order of steps, FIG. 2 is a cross-sectional view showing the processing situation in a reaction tube, and FIG. 3(a) ~(C) is a diagram showing a conventional method of creating a resonator Tsukuda in a step j@. DESCRIPTION OF SYMBOLS 1... Semiconductor tape wafer, 2... Etching-resistant coating, 10... Active layer, 20... Clad layer, 60
...Reaction tube, 100...Semiconductor multilayer film. Patent Applicant: NEC Co., Ltd. Agent Patent Attorney: First Ward

Claims (1)

[Claims] (1) A semiconductor laser wafer having an etching pattern made of an etching-resistant film on its surface is brought into contact with an etching gas such as hydrochloric acid gas, HBr, PCl_3, AsCl_3, etc. in a reaction tube, and the semiconductor laser is removed from the portions not covered by the etching pattern. A step of etching the crystal to form a step on the semiconductor laser wafer, a step of removing the etching gas from the reaction tube, and a step of supplying semiconductor raw material gas to form a semiconductor multilayer film on the side surface of the step formed on the semiconductor laser wafer. 1. A method for manufacturing a semiconductor laser resonator, comprising sequentially performing the following steps.