JPS5871682A - Semiconductor light emitting device - Google Patents

Abstract

PURPOSE:To form a transistor or a phototransistor which becomes a drive element of a semiconductor laser by forming the drive element which is composed of a part of a semiconductor layer, thereby utilizing the semiconductor layer. CONSTITUTION:Since a transistor is formed by utilizing the InP semiconductor layer of an n-p-n type structure of an n type InP layer 15, a p type InP layer 16 and an n type InP layer 19, the layer 19, a p type or n type InGaAsP layer 20, a p type InP layer 21, and a p type InGaAsP layer 22 are etched and removed except part of the layer 19 in the region to be formed with the transistor. The p side electrode of a laser and the emitter or collector electrode 23 of the transistor is formed on the layer 22, the n-side electrode of the laser and the collector or emitter electrode 24 of the transistor is formed on the layer 19 of the transistor forming region, and a base electrode 25 is formed on part of the layer 16 of the transistor forming region. In this laser, the semiconductor material of the n-p-n structure is used as the transistor to vary the potential of the electrode 24, thereby enabling to modulate the laser.

Description

[Detailed description of the invention] The present invention relates to a semiconductor light emitting device.

In recent years, attempts have been made to construct a composite device by combining a semiconductor laser with another active element 9 such as an FET, or by giving a semiconductor laser a new function other than a light emitting device.

In Figure 1, plFin type gallium arsenide (GaA
s) Substrate, 2 is a mouth-shaped gallium aluminum arsenic (G
aAIAs) 2 Rad layers e 3 FiGaAIAs
Active layer t4Fip type GaAlAs cladding layer, 5Fi
p-type GaAs layer.

6 is a p-type GaAl layer with high resistance, 7 is an n-type GaAs layer
PET active layer
0) Insulating layer, 1G is PET source electrode, 11FiF'
ET gate electrode, 12 is FET drain electrode, 13 is n
The side electrodes are shown respectively.

Conventionally, in order to integrate the laser (on the left side of the apparatus in Figure 1) and the drive element, here the FET (on the left side of the apparatus in Figure 1), it was necessary to provide two extra layers: a high resistance layer 6 and an FET operating layer 7. was there.

It is an object of the present invention to utilize the structure of the semiconductor layer of a semiconductor laser to provide a driving element composed of a part of a 2wI semiconductor layer, thereby forming a semiconductor laser and its driving element on the same substrate. It is an object of the present invention to provide a semiconductor light emitting device in which unnecessary semiconductor layers necessary for element formation are removed.

The present invention provides an active layer that causes laser oscillation, a p-cladding layer that has a larger forbidden band width than the active layer, and that defines a stripe-shaped current path with first and second cladding layers that sandwich the active layer. - a semiconductor laser device having a stripe type double hetero structure having a semiconductor layer having a Fin-p-n type structure on a substrate; A transistor or a phototransistor having a semiconductor layer having an n-p type or an amorphous n-p-n type structure is provided.

A p-n-p type stone provided in a semiconductor laser, or n
- A semiconductor layer with a p-n type structure is subjected to a p-n reverse bias during operation, so no current flows through the semiconductor layer, which serves as a current blocking region and defines the current path of the semiconductor laser. It was set up for the purpose. Therefore, in the present invention, the p-n
- The idea is to form a transistor or a phototransistor which becomes a driving element of a semiconductor laser by using a semiconductor layer having a p-type structure or an n-pn-type structure.

The present invention will be explained below using one embodiment of the present invention. FIG. 2 is a sectional view of a semiconductor light emitting device according to an embodiment of the present invention.

The manufacturing process of the semiconductor device shown in FIG. 2 will be briefly explained. An n-type indium phosphide (InP) substrate 14 is doped with impurities to a thickness of 10 cm to 10 cm.
~3Pr11 n-type InP layer 15. Impurities are 10”~
10” an-3 doped thickness 1.5)o>
The OF-type InP layer 16 is successively liquid-phase grown, and after death, the n-type InP layer 16 is
A V-shaped groove with a depth reaching the P layer 15 is formed. next,
#N-type InP grading layer doped with 1.17 to 10 cm of impurity in the V-shaped groove 17. P-shaped Ld
n-type indium gallium arsenic phosphorus (InGaA
sP) The active layer 18 is sequentially grown in liquid phase.

An n-type InP layer 19 with a thickness of 0.3 Pm is formed on the P-type 1nP layer 16 on which the 7-shaped tiles are not formed. Thickness 0.05P
A wm InGaAsP layer 20 is formed. At this time, the active layer in the groove has a degree of 0.15 prag at the center. P type 1
A P-type InP cladding layer 21 with a flat surface is formed by liquid phase growth of nP to a thickness of 1 to 15P+m from the surface of the InGaAsP layer 20, and then a P-type InGa with a thickness of 0.5P01 is formed.
The AsP layer 22 is grown using liquid acid. In order to electrically isolate the semiconductor laser and the transistor, etching is performed to a depth that reaches the layered InP layer 15 to form a trench for one isolation. Transistor un type InP layer 15, p type InP layer 16 and n
Since it is formed using an InP semiconductor layer having an n-p-n structure of type InPHII 19, a region where a transistor is to be formed has an n-type InP layer 19. N-type InGaAsP layer 2
0. p-type InP layer 21. The P-type InGaAsP layer 22 is removed by etching. - On the P-type InGaAsP layer 22 on which the semiconductor laser is formed, there is a P-side electrode of the laser and an emitter or collector electrode 23 of the transistor. Laser n1lK is applied on the n-type InP layer 19 in the transistor formation region.
Collector or emitter electrode of the transistor which also serves as a pole 24. A base electrode 25 is formed on a portion of the P-type InP layer 16 in the transistor formation region.

Note that the current path of the semiconductor laser is blocked by the p-n reverse bias of the P-type InP layer 16 and the n-type InP layer 19 formed outside the figure-7 groove, and the current flows only inside the figure-7 groove. Current flows.

In this laser, the laser can be modulated by using a semiconductor material with a v n p n structure as a transistor and changing the potential of the base electrode 24 . Mainly, the P-type 1nP layer 1 in the base, that is, the transistor formation region.
By irradiating light 26 to 6, the semiconductor layer having an npn type structure can be used as a phototransistor.

k With one chip, the receiver can amplify the light of several 41 W into a laser beam of several mW and send it out, and it can be used as an optical repeater. At this time, the wavelength of light that can be received by this phototransistor is shorter than the wavelength corresponding to the forbidden band of the semiconductor layer forming the base. Therefore, in this embodiment, since the semiconductor layer with the n-P-n type structure is formed of InP, light with a wavelength shorter than that of InP (1), such as gallium, aluminum, arsenic (()a
It is possible to receive photo-sounds of ALAs). Furthermore, depending on the purpose, the band gap can be reduced by using InPiIaGaAsP as the base to widen the wavelength range of light that can be received.

In order for n-p-n or Fip-n-p to function effectively as a transistor, it is necessary that the layer corresponding to the base be thinner than the diffusion length of minority carriers. This can be sufficiently achieved by setting the temperature to 5 Pm or less.

According to one embodiment of the present invention, an n-type InPJi 15 and a p-type InP provided to define a current path of a semiconductor laser
FIG. 3 is a cross-sectional view of a semiconductor device according to an embodiment of the present invention, which uses n-p-n type semiconductor layers of layer 16 and n-type InP layer 19. be.

In FIG. 3, 37 is an n-type InP substrate, 28 is an n-type InPf rad layer, 29 is an n-type InGaAsP active layer,
30 is P-type InP If rad layer, 31 is n-type InGaAs
P layer, 32 is P type InP layer, 33 is P type InGaAsP
34 indicates a P-side electrode, 35 indicates an N-side electrode, and 36#i pace electrode.

In this laser, the current path is blocked by the p-n reverse bias of the P-type InPjj rad layer 30 and the n-type InGaAs P layer 31, and the current is narrowed to the region where the n-type InGaAiP layer 31 is not formed. , the region becomes a current path. The transistor also has semiconductor layers for defining this current path, that is, an n-type InGaAsP active layer 29 and a p-type I
nP cladding layer 30 and n-type InGaAs P layer 31
A transistor or a phototransistor is formed using a semiconductor layer having a -pn type structure in the same manner as in the previous embodiment. In this device, since the active layer 29 is included in the tjn-pn type semiconductor layer, the impurity concentration cannot be freely selected depending on the transistor.

According to the present invention, n-p-it constituting a semiconductor laser
A transistor or a phototransistor can be formed on the same substrate by utilizing the structure of the TFP-NP type semiconductor layer. Therefore, there is no need to form an extra semiconductor layer to form a transistor or phototransistor.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 3 is a cross-sectional view of a device according to an embodiment of the present invention having a structure different from that of the semiconductor laser shown in FIG. 2. 6 High resistance layer 7 F'BT operation layer 15.1G, InP layer

Claims (1)

[Claims] an active layer that causes radar oscillation; first and second cladding layers that have a larger forbidden band width than the active layer and sandwich the active layer; and a p-n- layer that defines a stripe-shaped current path.
A striped double heterostructure semiconductor laser device having a p-type, 7- or n-p-n structure semiconductor layer on the substrate and a wrinkled semiconductor laser are provided on the substrate.
- A semiconductor light-emitting device comprising a transistor or a phototransistor having a semiconductor layer having an n-p type or n-p-n type structure.