JPH0443675A - Optoelectronic integrated device - Google Patents

Abstract

PURPOSE:To obtain a material structure suitable for an optoelectronic integrated device at a high production yield by forming the following in the same process: a p-layer and a buffer layer which are composed of the same material; an absorption layer and a channel layer which are composed of the same material; and an n-layer and an electron supply layer which are composed of the same material. CONSTITUTION:A layer 2 composed of p-InP or p-AlInAs, a layer 3 composed of i-InGaAs and a layer 4 composed of n-InP or n-AlInAs are formed sequentially on a semiconductor substrate 1 composed of p<-> InP by an epitaxial growth method. One part of the layers 2 to 4 is removed selectively; a double hetero pin photodiode is formed in one part and a HEMT is formed in the other part; a polyimide layer 7 is formed between the individual elements. The layer 2 forming the pin photodiode 5 constitutes a layer 8; the layer 3 forming the photodiode constitutes an absorption layer 9; the layer 4 forming the photodiode constitutes an n-layer 10. The layer 2 forming the HEMT 6 constitutes a buffer layer 11; the layer 3 forming the HEMT constitutes a channel layer 12; the layer 4 forming the HEMT constitutes an electron supply layer 13.

Description

DETAILED DESCRIPTION OF THE INVENTION [Pre-industrial Application] The present invention relates to an optoelectronic integration bi-layer in which a first device and an electronic device are integrated on the same semiconductor substrate.

[Conventional technology]

There are great expectations for the optical 7-channel integrated device as a device that can improve the performance, cost, and reliability of optical receivers and optical transmitters. However, it has not yet reached the level of practical use because optical devices and electronic devices, which have completely different functions and structures, must be integrated.

Therefore, technological innovations are desired in terms of crystal growth techniques, optical device structures, electronic device structures, integrated structures, and the like.

For this reason, various optoelectronic devices are being developed, such as the October 1988 Research Report of the Institute of Electronics, Information and Communications Engineers (Optical and Quantum Electronics).

Optical Communication System Research Group), P using rOMVPE method
This type of technology is disclosed in IN-HEMT Amplifier Reception 0EICJ. In other words, this document describes a PIN photodiode and a HEMT (high electron mobility transistor).
A receiving optoelectronic integrated device having a structure in which both are stacked and integrated is shown. In addition, there is also a receiving optoelectronic integrated device having a structure in which a PIN photodiode and a HEMT are separately grown as crystals and integrated.

[Problem to be solved by the invention]

However, the conventional PIN photodiode and the HE
For optoelectronic integrated devices with a structure in which MTs are stacked or in which crystals are grown separately, not only the crystal growth process becomes complicated (but also the manufacturing process for the entire device). This was a factor in reducing the manufacturing yield.

[Means to solve the problem]

The present invention has been made to solve these problems, and includes a semiconductor substrate made of semi-insulating 1nP or p-type (p) 1nP, and a p-1
A p layer constituting a photodiode made of nP or p-ANInAs, and an intrinsic (i-)I layer formed on this p layer.
An absorption layer constituting a photodiode made of nGaAs, and an n-type (n) InP or n-
The n-layer that constitutes the photodiode is made of Al InAs, and the H layer is formed on the semiconductor substrate and is made of the same material as the p-layer.
A buffer layer forming the EMT, a channel layer forming the HEMT formed on the buffer layer and made of the same material as the absorption layer, and an electron supply forming the HEMT formed on the channel layer and made of the same material as the n layer. It is formed with a layer.

Further, a spacer layer made of 1-1 nP or i-A, Q InAs is formed between the electron supply layer and the channel layer constituting the HEMT.

[Effect]

The p layer and buffer layer made of the same material, the absorption layer and channel layer made of the same material, and the square layer and electron supply layer made of the same material are manufactured in the same process.

Further, by forming a J1 sublayer between the electron supply layer and the channel layer of the HEMT, the electron-transport characteristics of the HEMT are improved.

〔Example〕

Next, according to an embodiment of the present invention, for long wavelength bands (13 to 1,
5511m) will be explained.

FIG. 1 is a sectional view showing the structure of an 0EIC according to a first embodiment of the present invention. This 0EIC is connected to the semiconductor substrate 1.
--1nP is used, and each layer is first formed by epitaxial growth in the structure shown in FIG. 2(a). That is, a layer 2 made of p-InP or p-A, Q InAs is formed by epitaxial growth on a semiconductor substrate 1 made of -1nP.

On this layer 2, a layer 3 made of 1-InGaAs is formed by epitaxial growth. On this layer 3, a layer 4 made of n-1n P or n-AΩ InAs is formed by epitaxial growth.

Furthermore, a part of the layers 2 to 4 formed in this way is selectively removed, and the layers 2 to 4 are divided into two (see figure (b)).
One of the 40° halves forms a double heteroluminium photodiode, and the other forms a HEMT.

As shown in FIG. 1, a polyimide layer 7 is formed between these elements for bathing and planarization.

Layer 2 forming the pln photodiode 5 constitutes the 0 layer 8 , layer 3 constitutes the absorption layer 9 , and layer 4 constitutes the 0 layer 10 . 0 layer 8 and 0 layer 1o lattice matched to absorption layer 9
Since it is formed of nP or Ag1nAs, it is not sensitive to optical signals in the long wavelength band of 1.3 to 1.55 μm. Further, the layer 2 forming the HEMT 6 is a buffer layer 111, the layer 3 is a channel layer 121, and the layer 4 is an electron supply layer 13. n-1nP or n-A, Ql
A relatively large conduction band discontinuity occurs at the interface between the electron supply layer 13 made of nAs and the channel layer 12 made of 1-InGaAs. HEMT6 is made of I n P / I nGaAs or AI I with such characteristics.
It is formed using an nAs/InGaAs heterojunction.

Further, an n-electrode 14 is formed on the 0 layer 10 of the pin photodiode 5, and an n-electrode 15 corresponding to this nts electrode is formed on the back surface of the semiconductor substrate 1.

Further, the electron supply layer 13'' of the HEMT 6 is provided with a drain electrode 16. A source electrode 17 and a gate electrode 18 are formed. By going through each of the above steps, a photoelectronic integrated device for light reception is formed.

The equivalent circuit of this device is shown in FIG.

The cathode of the pin photodiode 5 and the gate electrode 18 of the HEMT 6 are connected by a wiring metal (not shown). In addition, a resistor 19 (not shown) is connected to the cathode of the pin photodiode 5 and the drain electrode 16 of the HEMT 6.
．． 20 are connected.

In such a configuration, the pin photodiode 5 is reverse biased to apply an appropriate bias between the drain and source of the HEMT 6. When an optical signal is received by the pin photodiode 5 in this state, this optical signal is converted into an electrical signal, and this electrical signal is amplified and demodulated by the HEMT 6.

Note that the channel layer 1211 buffer layer 11 of HEMT6
Since the pin photodiode 5 and the HEMT 6 are in a reverse bias state, they are in a DC-isolated state.

The 0EIC according to this embodiment has two layers 8 and a buffer layer 1.
1, the absorption layer 9 and the channel layer 12, as well as the 0 layer 10 and the electron supply layer 13, are both made of the same material. Therefore, the 2 layer 8 and the buffer layer 11, the absorption layer 9 and the channel layer 12, and the 0 layer 10 and the electron supply layer 1
3 can be formed by the same epitaxial growth in the same process as described above.

FIG. 4 is a sectional view showing the structure of an 0EIC according to a second embodiment of the present invention, and the same reference numerals are used for the same or corresponding parts as in FIG. 1.

This 0EIC uses a semi-insulating 1 nP semiconductor substrate 2. In its manufacture, the layers 2 to 4 are laminated on the semiconductor substrate 21 by epitaxial growth, as in the first embodiment described above (see FIG. 2(a)).
reference). Next, the stacked layers 2 to 4 are selectively removed and divided into two parts: a side where the pin photodiode 5 is formed and a side where the HEMT 6 is formed. At this time, layers 3 and 4 of the laminated structure on the side where the plnln photodiode will be formed are removed, leaving layer 2, and the layer structure is further divided into two. One of the laminated structures divided into two on the pin photodiode 5 side is used to form an n-electrode 23, which will be described later.

The layers 2, 3 and 4 forming the pin photodiode 5 are two layers 8 and 4, similar to the first embodiment described above. The layers 2.3.4 constituting the absorption layer 9.0 layer 10 and forming the HEMT 6 are the buffer layer 11. The channel layer 12 constitutes a 7-power supply layer]3. Next, an insulating film 22 is formed on these laminated structures, and necessary portions are selectively removed. And plnln
Photodiode' 5 n-electrode on the removed part of the insulating film 22]
4 is formed, and an n-electrode 23 corresponding to this n-electrode is formed.
is formed on one of the laminated structures divided into two, leaving two layers 8. In addition, a drain electrode 16. A source electrode 17 and a gate electrode]8 are formed. Finally, place a heavy Hi between each laminated structure.
Polyimide 7 is formed due to the oxidation and banvation.

The structure of the second embodiment differs from the structure of the first embodiment only in the structure for forming the n-electrode 23 of the p i n diode '5. This is semiconductor substrate 2
This is due to the fact that semi-insulating material is used in 1. Therefore, the equivalent circuit of the device is shown in FIG. 3 in the same manner as in the above-mentioned embodiment, and the circuit operation is also the same. Also in this embodiment, the second layer 8, the buffer layer 11, and the absorption layer 9
Since the channel layer 12, the eleventh layer 10, and the electron supply layer 13 are formed from the same material, they can be manufactured in the same manufacturing process.

According to the 0EIC of the structure according to each of the above embodiments, the crystal growth process during manufacturing is simplified, and it becomes possible to obtain a device having a Brehner structure.

Further, by adopting a double epitaxial structure, it becomes possible to form an optoelectronic device without using ion implantation technology or impurity diffusion technology. Therefore, the entire manufacturing process is also simplified.

Furthermore, in each of the above embodiments, the electron transport characteristics of the HEMT 6 are improved by forming a spacer layer made of 1-1 nP or i-AΩ1 nAs between the electron supply layer 3 constituting the HEMT 6 and the channel layer 12. , the operating speed will be higher.

Note that the material of the electron supply layer 13 constituting the HEMT 6 is I.
When nP is used, 1-
It is preferable to form an AjJInAs layer or an IA,QGaInAs layer. This is because the Schottky characteristics of the gate electrode 18 formed in each of these layers are improved.

〔Effect of the invention〕

As explained above, according to the present invention, the p layer and buffer layer made of the same material, the absorption layer and channel layer made of the same material, and the [ ] layer and electron supply layer made of the same material are manufactured in the same process. . For this reason,
Not only is the crystal growth process of the optoelectronic integrated device simplified, but the entire manufacturing process is simplified. As a result, it becomes possible to provide a material structure suitable for an optoelectronic integrated device for long-distance optical communication with a high manufacturing yield.

By forming a spacer layer at +4J between the electron supply layer and the channel layer of the HEMT, the electron transport properties of the HEMT are improved and the operating speed of the device is increased.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a receiving opto-electronic integrated device according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view of the device in the manufacturing process of the opto-electronic integrated device shown in FIG. 1, and FIG. 1 is an equalization circuit diagram of the device shown in FIG. 1, and FIG. 4 is a small cross-sectional view of an optoelectronic r-integrated device according to a second embodiment of the invention. ]・1) -111P ten-conductor substrate, 5...double hetero pin photodiode, 6...HEM
T, 8...p layer, 9 absorption layer, 10...[] layer, 11...
...Buffer layer, 12..Channel layer, ]3..Electron supply layer, 2],,,,'1' Insulating 1nP. ]4 +7 18 16 (1'

Claims (1)

[Claims] 1. A semiconductor substrate made of semi-insulating InP or p^-type InP, and a p-type InP formed on this semiconductor substrate.
Or a p-layer constituting a photodiode made of p-type AlInAs and an intrinsic InGaA layer formed on this p-layer.
an absorption layer constituting a photodiode consisting of s, and an n-type InP or n-type AlInA formed on this absorption layer.
an HEM formed on the semiconductor substrate and made of the same material as the p layer;
A buffer layer forming T, a channel layer formed on this buffer layer and forming a HEMT made of the same material as the absorption layer, and a HEMT formed on this channel layer and made of the same material as the n layer. An optoelectronic integrated device comprising an electron supply layer. 2. The optoelectronic integrated device according to claim 1, characterized in that a spacer layer made of intrinsic InP or intrinsic AlInAs is formed between the electron supply layer and the channel layer constituting the HEMT.