JPS63164321A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To facilitate the formation of etching section making an angle of 45 deg. by a method wherein a substrate comprising III-V compound semiconductor or mixed crystal thereof is etched using an etching solution with an etching mechanism high in rate of reaction. CONSTITUTION:A photowaveguide 11 and a semiconductor layer 12 comprising III-V compound semiconductor are provided on the same group compound semiconductor substrate 10 with plane (100) turned by 10 deg. on the axis in the direction of [0-11]. The interface of laminated layer is to be a plane (100) turned by 10 deg. on the axis in the direction of [0-11]. An etching mask 13 on the borderline in the direction of [0-11] is formed on the layer 12. Finally, the surface is etched using an etchant with etching structure in high rate of reaction. In such a constitution, the III-V semiconductor is provided with the zincblende type structure so that etching speed thereof may be successively decelerated on the surfaces planes of (-1-1-1) (100) and (111) to form an etching section 14 making upward angle of around 55 deg. with the surface or the interface of laminated layer as well as another angle of 45 deg. with the interface of laminated layer of the photowaveguide 11.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing a semiconductor device widely used in industry, and in particular to a method for manufacturing a semiconductor device that is widely used in industry. Provides a manufacturing method.

BACKGROUND OF THE INVENTION Recently, the importance of semiconductor laser devices as light sources or optical functional elements has been widely recognized in optical-related industrial fields such as optical communication, optical measurement, and optical calculation, and research and development have been actively conducted in various fields. It is starting to be put into practical use.

By the way, the semiconductor laser devices currently in practical use are
Most of the devices have a structure in which the laser beam is extracted in a direction transverse to the surface of the semiconductor substrate on which the device is manufactured. On the other hand, there are many advantages such as high output with laser arrays, the superiority of light in parallel processing, greater flexibility in realizing monolithic optoelectronic integrated circuits, batch processing in the device manufacturing process, and ease of wafer testing. Surface-emitting semiconductor laser devices (which extract all of the laser light in the direction perpendicular to the substrate surface), which can be expected to have advantages, have begun to attract attention, and are being developed and researched in various fields.

Figure 3 shows examples of surface-emitting semiconductor laser devices that are currently being proposed or studied.
Mppl, Phys, Lett,, 31 (8),
15.

0 cuober, -1977, p. 524)
and Figure 4 (“Applied Physics Letters” Z, L, Liau, etal, ppl, P
hys, Lett, 46(2).

15, January, 1985, p. 1
15).

FIG. 3(!L) is a sectional view of the surface emitting semiconductor laser device, and FIG. 3(b) is a perspective view of the device. With the same device,
The reflective surface 2 intersects at an angle of 45° with the laminated interface of the optical waveguide (active layer) 1, so that the optical waveguide (active layer) 1
Surface emission 3 is obtained by changing the traveling direction of the laser beam by 90 degrees.

FIG. 4 is a cross-sectional and perspective view of a surface emitting semiconductor laser device of a different type from that shown in FIG. In this device, the traveling direction of laser light emitted from a semiconductor laser section 4 having a Fapley-Perot resonator is changed by 90 degrees by a reflecting surface 6 that intersects with this at an angle of 46 degrees.
Surface emission 6 is obtained.

FIG. 5 is a process diagram showing a method for manufacturing the reflecting surface 6 and the Fapley-Perot resonator end face 7 shown in FIG.

First, etching is performed using the 5102 mask 8 up to the active layer 9 (FIG. 5(a)). Next, 510
2. The mask 8 is partially reduced to zero width and peeled off to S), and etched using this to obtain a step-like etched shape (FIG. 5b). Finally, remove all 5102 masks 8, and remove 690 in H2 and PH atmosphere.
Mass transport is performed by heating at ~740″C to obtain the mirror surface 6 and end surface 7 (sixth
Figure C).

Problems to be Solved by the Invention As stated above, a surface that intersects at an angle of 45° with the cross section of the optical waveguide centering on the surface emitting semiconductor laser device? Forming technology has become extremely important. but,
The only concrete method to achieve this that has been proposed is the method shown in Figure 6.
It consists of step wet etching and mass transport, and the process is complicated and it is difficult to control reproducibility due to mass transport. Also, usually
Optical waveguides, active layers of semiconductor laser devices, etc. are formed on simple lattice planes such as the (100) plane of a semiconductor substrate, so they do not exhibit reaction-limiting (lattice plane orientation dependence) or diffusion-limiting (isodirectional) properties. There have been problems such as the inability to accurately form a 46° surface using wet etching alone.

Means for Solving the Problems In order to solve the above-mentioned problems, in the present invention, the surface or the laminated interface where the optical waveguide is entirely formed has the [011] (or [011]) direction as its axis and the (1oO) direction. 10°
[011] (or C
An etching mask having a boundary line along the Ol 1 :l ) direction was formed, and this was etched using an etching solution having a reaction rate-limiting etching mechanism.

When etching a group V compound semiconductor using an etching solution having an action-reaction rate-limiting etching mechanism,
Due to the fact that the I-V group compound semiconductor has a zincblende structure fr, its etching rate is similar to that of the (111) plane (
Group V elements are on the surface side).

The speed decreases in the order of (1oO) plane and (111) plane (surface side of group I elements) (for example, "Journal Op Machiatorial Science 7S J B, τuok, J0MILt6r
.

801,. 10, 1975. p. 321). That is,
When the surface or lamination interface is a (100) plane, 1-
If an etching mask having a boundary line along the [011] (or [011]) direction is formed on a substrate made of a V-group compound semiconductor, and this is etched using the etching solution, the etching cross section will be as follows. (11
1) (or equivalent), the angle with the surface or laminated interface is about 56°, and the direction is upward (or downward). Note that when the mask has a stripe shape, it is a mesa type (or an inverted mesa type).

Therefore, in the present invention, the surface or lamination interface is [1:o
ll :L (or [011]) direction as the axis (1
00) When the surface is rotated by about '1510'■
- By using a substrate made of a V-group compound semiconductor and subjecting it to the etching process described above, the etched cross-sectional shape is the same as that described above, and the angle thereof is 45°.
(=66°-10°) can be realized.

Embodiment An embodiment of the present invention is shown in FIG. First, the surface is 100) with the [011] direction as the axis.
An optical waveguide 11 made of a homogeneous semiconductor is entirely formed on a {circle around (1)-v} group compound semiconductor substrate 10, which has a surface rotated by about .degree., and a homogeneous semiconductor layer 12 is provided thereon (2L). Here, when the present invention is used in a surface emitting semiconductor laser device, 1
Q, 11, and 12 are the cladding layer, active layer, and cladding layer, respectively. 10, 11.1 formed by the above method
Similar to the surface of the substrate 1o, the laminated interface of the substrate 2 has a [011
] direction is the axis and the 100) plane is rotated by about 10 degrees. Next, an etching mask 13 having a boundary line along the [011] direction is formed on the semiconductor layer 12 (b). Finally, etching is performed using an etching solution having a reaction-rate-limiting etching mechanism. In this case, for example, when the l-V group compound semiconductor is InP, an HCl solution can be used as the etching solution. This situation is shown in FIG. The figure shows XnP(
100) This graph shows the etch depth versus etching time when a stripe mask is formed on the surface along the [011] direction and etched using f HOI solution (26°C). At this time, when the etched surface becomes a (111) (J3 or equivalent) plane, the progress of etching becomes extremely slow (at about 10 seconds in the figure).

That is, it has been demonstrated that the HCJ solution has a reaction rate-limiting etching mechanism for InP.

In this way, by using an etching solution that has a reaction rate-limiting etching mechanism, the surface can be easily etched (111
) (, i or equivalent) planes can be etched. Therefore, in the present invention, it is possible to easily realize the etched cross section (reflecting surface) 14 that forms an angle of 46° with the laminated interface of the optical waveguide (or active layer) 11.

Effects of the Invention As described above, the present invention provides a substrate surface or an optical waveguide,
46° to the laminated interface of the active layer, etc. of a semiconductor laser device
It is possible to easily realize etched cross sections that intersect at an angle of have a positive effect.

[Brief explanation of the drawing]

Fig. 1 is a process diagram showing a method for manufacturing a semiconductor device according to an embodiment of the present invention, Fig. 2 is a characteristic diagram showing the etching situation when InP is etched with HCI solution, and Fig. 3 is (a, b).
) A sectional view and a perspective view of a conventional surface emitting semiconductor laser device, FIG. 4 is a perspective view of a conventional surface emitting semiconductor laser device, and FIG. 6 is a process diagram of a conventional surface emitting laser device. 10... Substrate, 11... Optical waveguide (or active layer), 2, 14... 46° reflective surface,
3, 6... surface emitting, 13... etching mask. Name of agent: Patent attorney Toshio Nakao and 1 other person
1 Figure (b) @ [(7TI) direction ((1)
/+ Figure 2 Etting time review (seconds) Figure 3 Figure 4 v Figure 5 Procedural amendment January 14, 1932 2 Title of invention Method for manufacturing semiconductor devices 3 Person making the amendment Relationship with the case Patent applicant address: 1006 Kadoma, Kadoma City, Osaka Prefecture Name
(582) Matsushita Electric Industrial Co., Ltd. Representative Tani
Akio I 4 Agent 571 Address 1006 Oaza Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. Specification 1 Name of the invention Method for manufacturing a semiconductor device 2 Claims axis (10o) An etching mask having a boundary line along the (011:] (or [011]) direction is formed on the substrate, which has a plane rotated by about 100 as the surface or lamination interface. A method for manufacturing a semiconductor device characterized by etching using an etching solution having a reaction rate-limiting etching mechanism. It relates to manufacturing methods, particularly useful manufacturing methods for optical-related semiconductor devices such as semiconductor lasers, optical waveguide circuits, and optoelectronic integrated circuits. In recent years, the importance of semiconductor laser devices as light sources or optical functional devices has been widely recognized, and research and development efforts have been actively conducted in various fields, leading to their practical application. The semiconductor laser device is
Most devices have a structure that emits laser light in a direction transverse to the surface of the semiconductor substrate on which the device is manufactured. On the other hand, there are many advantages such as high output with laser arrays, the superiority of light in parallel processing, high flexibility when realizing monolithic optoelectronic integrated circuits, batch processing in the device manufacturing process, and ease of QF testing. Surface-emitting semiconductor laser devices (which emit laser light in a direction perpendicular to the substrate surface), which can be expected to have the following characteristics, have begun to attract attention, and are being developed and researched in various fields. Examples of surface-emitting semiconductor laser devices currently being proposed or researched are shown in Figure 3 (Applied Physics Letters, J, 3pringTh0rpl!1).
．． Mpp1. Phys, Lett, 31 (s), 1
5. 0 cuobar, 1977, p, 524
) and Figure 4 (“Applied Physics Letters” Z, L, Liau, etal, , Mp.
pl, Phyg, Lett, 46(2
), 15, January, 1985, p.
, 115). FIG. 3 & is a sectional view of a surface emitting semiconductor laser device, and FIG. 3 is a perspective view of the device. The device uses an optical waveguide (
By changing the traveling direction of the laser light in the optical waveguide (active layer) 1 by 90' by the reflecting surface 2 which intersects at an angle of 46° with respect to the lamination interface of the active layer 1, surface emitting light 3 is generated.
I am getting . FIG. 4 is a perspective view showing a part of a surface emitting semiconductor laser device of a type different from that shown in FIG. 3 in cross section. In this device, the traveling direction of laser light emitted from a semiconductor laser section 4 having a Fabry-Perot resonator is changed by 90' to a reflecting surface 6 that intersects with this at an angle of 46 degrees. , surface emission 6 is obtained. FIG. 6 is a process diagram showing a method of manufacturing the reflective surface 6 and the Fapley-Perot resonator end face 7 shown in FIG. First, etching is performed using the SiO□ mask 8 up to the active layer 9 (FIG. 6a). Next, the 5in2 mask 8 is partially peeled off (width S) and etched using this to obtain a step-like etched shape (FIG. 5b). Finally, all the 5in2 masks 8 are peeled off, and 690~74
By heating at 0'C', mass transport is performed and the mirror surface 6 and end surface 7 are obtained (FIG. 5C).
). Problems to be Solved by the Invention As stated above, the technology of forming a surface that intersects at an angle of 46° with the cross section of an optical waveguide is extremely important, especially in surface-emitting semiconductor laser devices. It has come. but,
The only concrete method that has been proposed for achieving this is the method shown in Figure 6.
It consists of step wet etching and mass transport, and the process is complicated and it is difficult to control reproducibility due to mass transport. Also, usually
Optical waveguides, active layers of semiconductor laser devices, etc. are formed on simple lattice planes such as the (100) plane of a semiconductor substrate, so they do not exhibit reaction-limiting (lattice plane orientation dependence) or diffusion-limiting (isodirectional) properties. There have been problems such as the inability to accurately form a 46° surface using wet etching alone. The present invention solves these problems and aims to make it possible to easily obtain a 46° etched cross section. Means for Solving the Problems In order to solve the above-mentioned problems, in the present invention, the surface or the laminated interface forming the optical waveguide has the [011] (or [011]) direction as its axis and the (100) plane. Using a substrate made of an IV group compound semiconductor, the plane of which is rotated by about 10 degrees, the plane is rotated by about 10 degrees.
11) Measures were taken such as forming an etching mask having a boundary line along the ) direction and etching this using an etching solution having a reaction rate-limiting etching mechanism. When etching a ■-V group compound semiconductor using an etching solution that has an action-reaction rate-limiting etching mechanism, ■
- Due to the fact that the V group compound semiconductor has a zincblende structure, its etching rate is on the (tit) plane (the V group element is on the surface side). It slows down at the beginning of the (100) plane and (111) plane (group ■ elements are on the surface side) (for example, ``Journal of Machiacial Sci:t, 7th J B, Tuck, J, Mater
. SOi,, 10.1975. (See p. 321). That is, when the surface or lamination interface is a (100) plane, an etching mask having a boundary line along the [0〒1] (or (011)) direction is formed on a substrate made of a -V group compound semiconductor. However, if this is etched using the above etching solution, the etched cross section will be a (111) (or equivalent) plane, the angle with the above surface or lamination interface will be about 550, and the direction will be upward. Steam (or downward). Please note that the mask is
ゞ゛2 2) If it is live, it is mesa type (or reverse mesa type)
It is. Therefore, in the present invention, the surface or lamination interface is [0〒1
] (or [011]) direction as the axis 100 )
When the surface is rotated by about 10 degrees, by using a substrate made of a ■-■ group compound semiconductor and etching it using the above-mentioned process, the etched cross-sectional shape is the same as that described above. The angle is 46° (=66°−
1o') can be realized. Embodiment An embodiment of the present invention is shown in FIGS. 1a-c. First, the surface is 100) with the (0-1) direction as the axis.
When the surface is rotated by approximately 0, an optical waveguide 11 made of a homogeneous semiconductor is formed on the ■-■ group compound semiconductor substrate 1o, and a homogeneous semiconductor layer 12 is provided thereon (FIG. 1a). Here, when the present invention is used in a surface emitting semiconductor laser device, 10°, 11° and 12° are a cladding layer, an active layer, and a cladding layer, respectively. 10 and 11 formed by the above method
The laminated interface of ゜12 is similar to the surface of the substrate 1o, ゜12.
The surface is obtained by rotating the 100) plane by about 100 around the 11] direction. Next, on the semiconductor layer 12 (oal
) An etching mask 13 having a boundary line along the direction (FIG. 1b) is formed. Finally, etching is performed using an etching solution having a reaction-rate-limiting etching mechanism. In this case, for example, the ■-v group compound semiconductor is In
When P, an HC1 solution can be used as the etching solution. This situation is shown in FIG. Figure 2 shows the etching results when a stripe mask is formed along the (011) direction on the InP (100) surface as shown in Figure 2a, and this is etched using HO1 solution (26°C). It shows the etch depth versus time. At this time, when the etched surface becomes a (111) (or equivalent) plane, the progress of etching becomes extremely slow (at about 10 seconds in Figure 2). That is, it has been demonstrated that the HC1 solution has a reaction-rate-limiting etching mechanism for InP. As described above, by using an etching solution having a reaction rate-limiting etching mechanism, it is possible to easily obtain an etched cross section whose surface is a (111) (or equivalent) plane. Therefore, in the present invention, it is possible to easily realize an etched cross section (reflecting surface) 14 that forms an angle of 46° with the laminated interface of the optical waveguide (or active layer) 11 (FIG. 1C). Effects of the Invention As described above, the present invention provides a substrate surface or an optical waveguide,
46° to the laminated interface of the active layer, etc. of a semiconductor laser device
It is possible to easily realize etched cross sections that intersect at an angle of It will be done. 4. Brief description of the drawings Figures 1a-c are process diagrams showing a method for manufacturing a semiconductor device according to an embodiment of the present invention, and Figures 2a and b show the etching situation when InP was etched with an HO1 solution. FIGS. 3a and 3b are cross-sectional views and perspective views of a conventional surface-emitting semiconductor laser device, FIG. 4 is a perspective view of a conventional surface-emitting semiconductor laser device, and FIGS. It is a process diagram of an example surface emitting laser. 1o...Substrate, 11...Optical waveguide (or active layer), 2.14...46° reflective surface,
3.6... Surface emitting, 13... Etching mask. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure ″−°Execution statueゝEckeng 11% interval (−゛)′ 6 sects sect

Claims (1)

[Claims] When wet etching a substrate AB (A (B) is a III (V) group element or a compound of the same group) which is a III-V compound semiconductor, a mixed crystal thereof, or a laminated structure thereof, [ 0@
1@1] (or [011]) direction as the axis,
0) Using the above-mentioned substrate which has a surface rotated by about 10 degrees as a surface or a lamination interface,
] (or [011]) direction, and etching the etching mask using an etching solution having a reaction rate-limiting etching mechanism.