JPH01236681A - Manufacture of semiconductor laser - Google Patents

Abstract

PURPOSE:To protect an electrode, a wiring, an insulating film, and a protective film against damage at the removal of a mask by a method wherein an organic film is removed with O2 plasma after an etching mask is removed with an etching solution which contains HF. CONSTITUTION:An organic film 5 and an etching mask material 6 are successively formed on wafers 1-4 of a semiconductor laminated structure which includes an active layer, and the etching mask material 6 and the organic film 5 are patterned. And, the waters 1-4 are etched, the etching mask material 6 is removed with an etching solution which contains RF, and then the organic film 5 is removed with O2 plasma to form a resonator. As mentioned above, as a P electrode 4 and an SiO2 3 are covered with the photoresist 5 of an organic film, the P electrode 4 and the SiO2 3 are not corroded by HF.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for manufacturing a semiconductor laser, and particularly to an InP-based semiconductor laser capable of ultra-high-speed operation, or 0EIC.
The present invention relates to a method for forming a resonator of an InP semiconductor laser mounted on an optoelectronic integrated circuit (optoelectronic integrated circuit).

(Conventional technology) In recent years, with the advancement of optical communication technology, there has been a strong demand for higher performance of InP-based optical devices. 0EI monolithically integrated circuit
The realization of C is desired. To realize these devices, it is necessary to shorten the laser cavity or form a laser cavity that does not affect the layout of the electronic circuit. For this purpose, it is necessary to form a resonator without using wafer cleavage, and a dry etching method is known as one of such methods. In the InP dry etching method, the etching rate of the InP mixed crystal is generally low, and if a photoresist is used as a mask, a sufficient selectivity cannot be obtained, so a metal or dielectric is used as the mask. As a conventionally known mask, a method was known in which T i O2 was formed directly on a wafer (1981, Nako Bond Information and Communication Society, Semiconductor Transistor Research Group Food 5SD85-117).
.

(Problem to be Solved by the Invention) However, it is necessary to remove the mask after dry etching is completed, and although masks such as TiO2 can be removed with an etching solution containing IF, dry etching usually This is done after forming electrodes, wiring, an insulating film, and a protective film on the mask, and if an etching solution containing HF is used to remove the mask, there is a problem in that it soaks these parts.

Therefore, the purpose of the present invention is to solve such problems,
An object of the present invention is to provide a method for forming a common ffA type acid in an InP semiconductor laser without soaking electrodes, wiring, insulating films, and protective films during mask removal.

(Means for Solving the Problems) In order to solve the multiple problems, the present invention provides a method for manufacturing a semiconductor laser, in which a semiconductor laser is manufactured on a wafer having a semiconductor laminated structure including an active layer. A step of sequentially forming A and an etching mask material, a step of patterning the etching mask material and the organic film, and a step of etching the wafer.

The method is characterized in that a resonator is formed by a step of removing the etching mask material with an etching solution containing HF and a step of removing the organic film with O2 plasma.

(Example) Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a method according to an embodiment of the present invention, and is a diagram showing the process of forming a semiconductor laser cavity in more detail. FIG.

As shown in the figure, first, a buried semiconductor laser layer 2 made of InP and InGaAsP was formed on a substrate 1 made of n-type In, P, and a current confinement window made of 51023 was formed on the active layer. T i / P t / on top
A P electrode 4 of Au is formed (FIG. 1(a)).

Next, an organic photoresist 5 is applied, and Ti is further deposited to a thickness of 5000 nm to form an etching mask 6.
[Patterning the etching mask 6 so as to cover i4 The organic photoresist 5 is patterned using the zero-order etching mask 6 (FIG. 1 (6)).

Next, the semiconductor laser layer is etched by dry etching using Cρ2 gas to form a resonator (Fig. 1(c)
)).

Next, the etching mask 6 is removed using HF, and the organic photoresist 5 is further removed by plasma etching using O2 gas (FIG. 1(d)).

Next, an n-electrode 7 made of A u G e / N i / A u is formed, and the semiconductor laser is completed (see Fig. 1 (
e)).

In this embodiment, P electric W! Since the 4.5iOi3 is covered with the organic photoresist 5, the Pt14 and 5iOi3 are not attacked by HF when the etching mask 6 is removed.

Furthermore, the 02 plasma used to remove the organic photoresist 5 is P-electric vi! 4,5i023. It does not invade the '+4' loser layer.

Note that the laser structure to which the present invention is applied is not limited to the above-mentioned structure, and any structure may be used, and the etching mask used in the present invention may be of any structure as long as it can be removed with HF. Further, in the present invention, any type of aplA may be provided between the wafer and the etching mask.

(Effects of the Invention) As described above, according to the method of the present invention, an InP-based semiconductor laser capable of ultra-high-speed operation or an InP-based semiconductor laser mounted on a high-speed, low power consumption 0EIC can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a process diagram showing an embodiment of the present invention. In the figure, 1 is a substrate, 2 is a semiconductor laser layer, and 3 is a 5i
02.4 is a P electrode, 5 is an organic photoresist, 6 is an etching mask, and 7 is an N electrode. (a) (c) Figure 1 (d) (e) Figure 1

Claims (1)

[Claims] A step of sequentially forming an organic film and an etching mask material on a wafer having a semiconductor stacked structure including an active layer, a step of patterning the etching mask material and the organic film, a step of etching the wafer, and a step of etching the etching mask. A method for manufacturing a semiconductor laser, comprising forming a resonator through a step of removing the organic film with an etching solution containing HF and a step of removing the organic film with O_2 plasma.