JPS5929477A - Light-emitting element - Google Patents

Abstract

PURPOSE:To obtain the light-emitting element having a light-emitting diode and its driving element monolithicly integrated on the semiconductor substrate using the material of InGaAsP mixed crystal whereon a high resistivity semiconductor layer is hardly formed. CONSTITUTION:On both sides of an N type InP semiconductor substrate 31, the second semiconductor layers 321 and 322 of approximately 2 mum in thickness consisting of N type InP, the third semiconductor layers 331 and 332 of approximately 2mum in thickness consisting of N type InP, the third semiconductor layers 331 and 332 of approximately 1mum in thickness consisting of In1-xGaxAsyP1-y,the fourth semiconductor layers 341 and 342 of approximately 1mum in thickness consisting of P type InP, and the fifth semiconductor layers 351 and 352 of approximately 1mum in thickness consisting of N type In1-zGazAswP1-w are formed by performing a vapor-phase growing method. When a positive voltage is applied to an electrode 38, electrons are induced on the interface where the P type semiconductor layer 342 and an insulating from 37 come in contact with each other, an electron current runs from an electrode 39 and along the interface of the insulating film and the semiconductor layer, and the electrons are injected to the semiconductor layer 331 of a light-emitting part 21 which is an active layer. Also, a hole current runs from an electrode 42 through an impurity diffusion layer 40, said hole current is injected to the semiconductor layer 331, a light emission is generated by the recoupling of the electron and the light is picked up to outside.

Description

[Detailed Description of the Invention] The present invention monolithically integrates a light emitting diode and its driving element on the same semiconductor substrate)Y; J', rl,
(Regarding the light emitting element for i.

Light-emitting diodes are already in practical use as inexpensive light sources for optical communications using low-transmission-loss optical fibers, but if the driving elements are integrated on the same semiconductor substrate, manufacturing costs can be reduced and the device can also be made smaller. Ru. On the other hand, crystal growth techniques such as vapor phase growth are being developed to produce optical semiconductor devices such as light-emitting diodes. It is something to do.

As a light emitting element in which a light emitting diode and a driving element are integrated, for example, a light emitting element as shown in FIG. 1 is known.

FIG. 1 is a cross-sectional view of a light emitting diode with a double heterostructure (JaAlAsloaAs) integrated with a field effect transistor (1), in which 13 is an active semiconductor layer, 12
is an It-type cladding layer, and 14 is a p-type cladding layer, each of which is 1) type U; Io9A/? o, +As, n-type Ua
o7hl o3As 1p type (Ja 0.7AeO,
It consists of 3AFl. 15 is! ] type (hA, s.

16 is non-doped OaO, 7A with high resistivity
This is an isolation layer consisting of 10.3AS. 17
is 11 type GaAs118 is AuGe-Ni 1・rain electrode, 19 is A, 1 gate electrode, 23 and 24
is the source 11 electrode and the source electrode part is kuGe −
N i 1 Source' The part of the navigation pole 24 is A, 11/Zn
/Au. Further, 11 is an n4F, 'J-GaAs semiconductor substrate, and 25 is an AuGe-Ni 1W pole.

FIG. 2 is an equivalent circuit diagram of the element shown in FIG. The light emitting diode and the field effect transistor are separated by an isolation layer 16. However, with this kind of structure, there is no problem with materials such as A11O;+'hs, where semiconductor layers for isolation with high resistivity can be easily produced, but it is difficult to produce semiconductor layers with high resistivity. It cannot be applied to semiconductor materials. In0aA is known as a semiconductor material especially in the 111m band where optical fiber exhibits low dispersion and low loss characteristics. '$ mixed crystal is AdGa
The higher the As type, the easier it is (the formation of a semiconductor layer with resistivity is difficult, and structures like rJsl and 1 are often applied)
((stomach.

The present invention was made in view of the above-mentioned drawbacks, and 2) it is possible to manufacture a light emitting diode and its driver using a material that has high resistivity and 2) facilitates the production of a semiconductor layer.
(Providing an effective tjl, lj structure using a light-emitting element that has been modified)
-

The light emitting device of the present invention has a first conductor 11τ, type '! 1
No. 1, 4, etc. are applied to both sides of the substrate, respectively. '+tl-2 semiconductor layer having li type, third semiconductor layer and first conductor ↑If
, type kichi [4,:+'? A fourth semiconductor layer having a second conductive turtle shape H and a fifth semiconductor layer having a first conductive arch shape are formed, and the second semiconductor layer and the fourth semiconductor layer are formed.
The semiconductor layer is formed so that the third half 2p month 4'I·1''i is smaller than the third half, the co-gang band width is large, and the effective 1f ratio is small, and one side of the semiconductor substrate is used as a light emitting part and the other side is is the driving part, and the front part has a circular concave shape with a depth that extends from the surface of the fifth semiconductor layer to the inside of the E:i72 half 2. body layer in the moving part. J1"J, a projecting window is formed, and an insulator 11' is installed on the side wall of the light extraction window.
A pole is formed through S, and an electrode is formed in a portion of the surface of the fifth semiconductor layer where the light extraction window is not formed, and in the front light emitting part, front n
A current injection means is formed in a portion of the V fifth semiconductor layer facing the light extraction window.

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 3 is a cross-sectional view 1 of one embodiment of the present invention. I
It was fabricated using nGaAsJ,' mixed crystal.

In the figure, 31 is an 11-type Inl' semiconductor substrate;
21 and 322 are second semiconductor layers made of n-type InP and have a thickness of approximately 2 μIll; 331 and 332 have a thickness of approximately 1/1
The third semiconductor layer 1v, 341 and 342 are made of m's 1 old -
is an n-type ■nt-zG a with a thickness of approximately 1/1 m 7. AFI
This is a fifth semiconductor layer made of WLF I-W, and is simultaneously formed on both sides of the semiconductor substrate 31 by vapor phase growth. The amount of light emitted including the third semiconductor layer 331 where the lower side of the semiconductor substrate 31 is an active layer? 1 to 21, and the upper side is a drive section 22 including electrodes for control and the like having a function of switching light emission. ;3 (i is 1. drive) 1 (~22
A circular, concave ()' (, H
V, is a projecting window. 37 is a side wall of the light extraction window 36 (
Approximately 1000'h thick formed by CV11 method
The insulating film 38 is made of S+02 and is an Al electrode formed on top of the insulation film 1111 to control the temperature.

39 is an electrode made of homogeneous An(lc-Ni). 40 is an electrode made of homogeneous An(lc-Ni);
.

The impurity diffusion 11 formed by
This part of the fifth layer 351 made of In+-zGazAswL'+-w is p-type (4). 41 is 5i02.42 is 'J' i/P t /
The electrode is made of Au. When in use, a positive voltage is applied to the electrode 42, and the drive unit 22 is grounded.
In the case of J7.5 in this embodiment, in which the second semiconductor layer 322 is of the 11 type and the fourth semiconductor layer 342 is of the p type, this period becomes a reverse bias state, so 'Ill: 4jK : (applied to 8) When the voltage is 0, or negative 'tit pressure, no current flows between tlf, 41□□□39 and 111.pole 42, and no light is emitted. When an electric voltage of 1 voltage is applied, 1) electrons are induced at the interface where the fourth semiconductor layer 342, which is firm, and the insulation layer 37c!: are in contact, and f[1
Electrons flow from 9 to the interface between the insulating film 37 and the semiconductor layer and are injected into the third semiconductor layer 331 of the light emitting section 21, which is an active layer.

Further, the hole current flows from the electrode 42 through the impurity diffusion region 10, and a positive ratio is injected into the third semiconductor layer 331, and light emission occurs due to the recombination of the holes in the direction shown by the arrow in FIG. It is taken out to the outside t(μ).
/, l# 1.11 type of the third semiconductor layer 332 of 2 is not specified on the back, but if it is an n type, of course, and even if it is a p type, due to the above-mentioned effect, . It will be appreciated that a current path is induced for the electrons.

Since the diameter of the light balancing window 36 is 200 .mu.m in this embodiment, the circumference is approximately 6:30 .mu.In, making it possible to widen the width of the current path for electrons. As a result tlZ
& Approximately 70~ by applying a voltage of 1v to 3B
It can flow a low current of 80 mA. The current 41N is proportional to the thickness of the fourth semiconductor layer 342, and if the layer thickness is made thin enough to prevent breakdown, the current will increase further)
- It is possible to increase the value by 0. In this example, the electron current is controlled, but if the conductor (l type) of each semiconductor layer in this example is reversed, it becomes a light emitting element that controls the hole current. The mobility of electrons is slower than that of electrons, so it is not suitable for applications aimed at high-speed swinging.

The light emitting device of the present invention requires only one crystal growth using a technique such as a vapor phase growth method, has a single fil structure, and can be manufactured relatively easily. In addition, since the light emitting part and the driving part are integrated in one direction (semiconductor layer), it does not take up much space and is suitable for devices that require miniaturization.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional example, Fig. 2 is an equivalent circuit diagram thereof, and Fig. 3 is a 161-plane view of an embodiment of the present invention (11 and 31 are semiconductor substrates, 12 is an n-type cladding). layer, 1
3 is an active semiconductor layer, J4 is a p-type cladding layer, 15 and 1
7 is n-type 0aAs, IG is an isolation layer, 18 is a drain electrode, 19 is a gate electrode, 23 and 24 are source electrodes 4iζ, 32] and 322 are second semiconductor layers, 331
and 332 are third semiconductor layers, 341 and 342 are fourth semiconductor layers, 351 and 352 are fifth semiconductor layers, 36 is a light extraction window, 37 is an insulating film, 25, 38, 39 and 4
2 (ma'+it・1guku, /l() is the impurity expansion 11 (head mounted, 41 is S + 02.2L is the light emitting part, 22 is the driving part.) 1 Figure f 2 Mouth -5 section

Claims (1)

[Claims] A second semiconductor layer having a first conductivity type, a third semiconductor layer, a fourth semiconductor layer having a second conductivity type different from the first conductivity type, and a fourth semiconductor layer having a second conductivity type different from the first conductivity type, on both sides of a semiconductor substrate having a tn1 conductivity type 11L type. A fifth semiconductor layer having a type of 1 conductor 11T is sequentially formed, and the second semiconductor layer and the fourth semiconductor layer have at least a larger forbidden band width and a smaller refractive index than the third semiconductor layer. One side of the semiconductor substrate is a light emitting part, the other side is a driving part, and the driving part has a depth that reaches from the surface of the fifth semiconductor layer to the inside of the second semiconductor layer. A light extraction window having a circular concave shape is formed, an electrode is formed on the side wall of the light extraction window via an insulated film, and a portion of the surface of the fifth semiconductor layer where the light extraction window is not formed. electrodes are formed on the
A light-emitting element characterized in that, in the light-emitting portion, a '1'lj1 flow injection means is formed in a portion of the fifth semiconductor layer that faces the light extraction window.