JPH0594874A - Active element - Google Patents

Abstract

PURPOSE:To provide an active element provided with single crystal functional layer grown in an optimal growth orientation. CONSTITUTION:In an active element provided with a functional layer heteroepitaxially grown on a single crystal substrate 101, by offsetting the face of the single crystal substrate 101 the growth orientation of the functional layer 102 is controlled in a different orientation from the face orientation of the single crystal substrate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION Active devices manufactured by using an epitaxial growth technique, such as light emitting devices, light receiving devices, various electronic devices such as field effect transistors, and nonlinear optical devices, such as displays, LEDs, LASER, and printer head writing. It can be applied to devices.

[0002]

2. Description of the Related Art In the case of an electroluminescence device as an example of an active device, according to the prior art, (1) is formed on a single crystal Si (111) substrate.
11) ZnS heteroepitaxially grown in the plane orientation:
Electroluminescent device using Mn as light emitting layer (Japanease
Journal of Applied Physic
s Vol. 24, No. 8, August, 198
5, pp. L629-L631) or single crystal Si
An electroluminescent device having a light emitting layer of ZnSe heteroepitaxially grown in a (100) plane on a (100) substrate (Journal of Applied Physi).
cs 58 (2), 15 Jul 1985 002
1-8979 / 85 / 14793-04), but no electroluminescent device in which the growth orientation of the light emitting layer is controlled has been reported.

By the way, an active element such as an optical waveguide, a non-linear optical element, a laser or an electroluminescent element has an optimum growth orientation in its functional layer. In the case of an electroluminescent device using a ZnS-based material as a light emitting layer, high brightness is obtained with a device in which the plane orientation of the light emitting layer is a <111> plane, but the plane orientation of the light emitting layer is slightly smaller than the <111> plane. If the number of collisions of the accelerated electrons with atoms other than the emission center is reduced by increasing the interstitial distance in the direction of the electric field by shifting the distance, high brightness can be obtained even at low voltage driving.

However, the prior art only reports an active element having a functional layer heteroepitaxially grown in accordance with the plane orientation of a single crystal substrate.

[0005]

The present invention has been made in order to obtain a functional layer grown in an optimum orientation that is slightly deviated from the plane orientation of the single crystal substrate. The off angle is obtained by using a method such as polishing. It is an object of the present invention to provide an active device having a single crystal functional layer grown in an optimum growth direction by heteroepitaxially growing a functional layer on a single crystal substrate in which the optimum orientation is controlled.

[0006]

The structure of the present invention for solving the above-mentioned problems is to provide an active element heteroepitaxially grown on a single crystal substrate by offsetting the surface of the single crystal substrate to thereby increase the growth direction of the functional layer. Is an active element controlled in an orientation different from the plane orientation of the single crystal substrate.

The active element according to the present invention, by obliquely etching the surface of the single crystal substrate to form a plane orientation slightly different from the plane orientation of the single crystal substrate on the surface, and then learns the plane orientation of the surface to function. It is an active device obtained by heteroepitaxially growing a layer. In the above-mentioned active element, the growth orientation is controlled so as to have an optimal orientation plane for the operation of the functional layer.

In the electroluminescent device manufactured by the present invention, the interatomic distance in the electric field direction becomes slightly longer in the light emitting layer epitaxially grown in the plane orientation slightly tilted from the plane orientation of the single crystal substrate. In such a light-emitting layer, the number of times electrons accelerated by an electric field collide with atoms other than the light-emission center and the light-emission center can be efficiently excited. A light emitting device can be obtained.

Referring specifically to the drawings, FIG.
Shows schematically the relationship between the substrate 101 and the functional layer 102 of the present invention.

Semiconductor materials such as Si and Ge, Y ₂ O ₃ and Y
An oxide material such as SZ, Ta ₂ O ₃ , Sm ₃ O ₃ , Al ₂ O ₃ or MgAl ₂ O ₃ or a single crystal substrate 101 such as a fluoride material such as CaF ₂ , BaF ₂ or SrF ₂ is obliquely arranged. In the polishing or wet etching method, the etchant is selected and the etching time is controlled. In the dry etching method, the resist and the gas species are selected, and the etching time is controlled.
The surface having an optimum plane orientation is prepared for the device to be manufactured so that the angle is -20 °, preferably 0.5-10 °. LiNbO ₃ , ZnSe, PbTiO ₃ , PLT,
Non-linear optical materials such as LiTaO ₃ , PLZT, BaTiO ₃ , and SrTiO ₃ , ZnS, ZnSe, ZnS _X Se _X-1
ZnS with the above materials as the base material and Mn added as the emission center:
Mn-based material or Zn obtained by adding Cu to the above base material
S: Cu-based material. Or rare earth fluoride in the base material _{(TbF 3, ErF 3, NbF} 3, TmF 3, PrF 3, S
mF ₃ , DyF ₃ , HoF _3, etc.) added material, S
Using rS as a base material, Ce, Sm, Tb, Dy, and
By adding a material containing Er, Tm, Pr, Mn, or the like or a light emitting material containing CaS as a base material and Er or the like to the emission center as the functional layer 102, and heteroepitaxially growing on the optimum plane orientation described above, It is possible to obtain a functional layer having an optimum plane orientation learned from the plane orientation of As means for epitaxial growth, MO-CVD method (metal organic thermal decomposition), MBE method (Molecular-Beam-Ep) are used.
Itaxy), ALE method (Atomic-Layer-
Epitaxy), an electron beam vapor deposition method, a sputtering method, a plasma CVD method or the like is used alone or in combination.

[0011]

EXAMPLES The active element of the present invention will be described in more detail below with reference to examples.

Embodiment 1 An embodiment of the present invention will be described with reference to FIG.

A single crystal Ge substrate having a <111> plane orientation is used. The resistivity of the Ge substrate is 10 Ωcm. This single crystal Ge substrate was surface-polished so as to be tilted by 1 ° from the <111> plane orientation to obtain a substrate 201.

The newly obtained surface is polished to a mirror surface, and ZnS: Mn having a zinc blend structure in which 0.5 at% of Mn, which becomes an emission center, is added to the surface, is used as a substrate surface orientation with a thickness of 3000 Å as if it were MO. -Heteroepitaxial growth using a CVD method to form a light emitting layer 202 of an electroluminescent device.
And

On the light emitting layer 202 produced by the above method,
PbTi used as the insulating layer 203 is formed by using the MO-CVD method.
O ₃ is deposited to a film thickness of 3000Å. In this case PbTi
Although O ₃ does not become a single crystal, it is a film strongly oriented in the plane direction of the light emitting layer 202. Finally, ITO to be the transparent conductive film 204 was formed on the upper insulating layer by a sputtering method to a film thickness of 2000 Å to complete the electroluminescent device according to the present invention.

3 kHz is formed between the ITO film, which is the transparent conductive film 204 of the electroluminescent device manufactured by the above method, and the Ge substrate.
With the AC voltage of the frequency
It was observed from the TO side.

The light emission starting voltage of this electroluminescent device is 60V.
And the maximum emission luminance of 2000 cd / m ² is obtained. An element in which a light emitting layer and the like were similarly formed on a Ge (111) single crystal substrate which was not surface-polished,
The light emission start voltage is 20 V lower than that of the same observation as above, and the maximum brightness is improved by 20%.

As described above, in the electroluminescent device of the first embodiment according to the present invention, the light emission starting voltage is lower and the maximum brightness is improved as compared with the electroluminescent device in which the growth direction of the light emitting layer is not finely controlled. High brightness was obtained even in a low voltage driving state. Even in active elements such as optical waveguides and laser nonlinear optical elements, the optimum plane orientation of the functional layer exists, and as described above, the growth orientation of the growth layer is delicate by controlling the off set angle of the single crystal substrate surface. The characteristics of an active element having a single-crystal functional layer controlled in the above manner are improved.

[0019]

As described above, the function of the active element of the present invention is further improved as compared with the conventional active element using the single crystal substrate.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view for explaining the relationship between a substrate and a functional layer of the present invention,

FIG. 2 is a schematic cross-sectional view showing the configuration of the active element according to the first embodiment of the present invention.

[Explanation of symbols]

 101, 201 substrate 102 functional layer 202 light emitting layer 203 insulating layer 204 transparent conductive film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Miura, Takadate Kumanodou, Natori City, Miyagi Prefecture, 5-10, Ryokan Applied Electronics Research Laboratory, Inc. (72) Inventor, Koichi Haga, Takadate Kumanodo, Natori City, Miyagi Prefecture 5-10 Kyomakata Ricoh Applied Electronics Research Laboratories Co., Ltd.

Claims (1)

[Claims] 1. In an active device having a functional layer heteroepitaxially grown on a single crystal substrate, the growth direction of the functional layer is controlled to be different from the plane orientation of the single crystal substrate by offsetting the surface of the single crystal substrate. An active element characterized in that