JPH05283342A - Electron beam excitation vapor growth device and vapor growth - Google Patents

Abstract

PURPOSE:To reduce an entire of a growth device and to easily control the flow of raw gas by using a fine electron beam irradiating device which is composed of a semiconductor emitter of a cold cathode. CONSTITUTION:When voltages V1 and V1+V2 are applied between an Si substrate 20 and tungsten electrodes 23a, 23b by a fine electron beam irradiating device 2a, the Si substrate 20 becomes a cold cathode and the tungsten electrodes 23a, 23b become an anode. Then, a field across electrodes concentrates in a conic projection 21 of the Si substrate, a high field is generated and electron beam is emitted. That is, the projection 21 functions as a field emitting emitter for electron beam emission. Thereby, a large space for arranging an electronic gun in a growth device becomes unnecessary, flow of raw gas can be readily controlled and a semiconductor fine structure can be formed with good controllability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam excited vapor phase growth apparatus and a vapor phase growth method. More specifically, the present invention relates to a vapor phase growth apparatus and a vapor phase growth method for producing a semiconductor fine crystal structure represented by a quantum well wire or a quantum well box.

[0002]

2. Description of the Related Art MOC for fabricating semiconductor microstructures
Growth on a stepped substrate by the VD method and growth using a selective growth mask have been reported. In addition, recently, there is also a report of a growth method using an electron beam capable of narrowing the beam to a size (several hundred Å) in which a quantum effect occurs (for example, see the Journal of Spring Applied Physics 30a-S-5 in 1990). .. A conceptual diagram of this device is shown in FIG. This apparatus is composed of a reactor section 101 for growing and an electron beam generating section 102 for promoting the growth. A susceptor 10 for mounting a growth substrate (hereinafter referred to as a growth substrate), for example, GaAs, in the reactor 101.
3 and a heater 105 for heating the susceptor and the like are housed therein, and raw material gases such as AsH ₃ , TMG and TMA are introduced and exhausted. Also, the electron beam generator 102
11 is based on the conventional filament heating method. As shown in FIG.
2 to generate an electron beam 104 by thermionic electron emission,
Acceleration is performed by the positive and negative electrodes 113 and the growth substrate is irradiated by the lens 114. According to this method, GaA irradiated with an electron beam
Adsorption and decomposition reaction of the raw materials (AsH ₃ , TMG, TMA) on the surface of the s substrate is promoted, and as a result, it becomes possible to form a fine structure growth layer having a size of the electron beam diameter.

[0003]

The conventional apparatus shown in FIGS. 10 and 11 is an application of an electron microscope (SEM), and the structure of the electron gun is large. Therefore, there is a problem that the entire reactor becomes large and it becomes difficult to control the flow of the raw material gas. Also, since there is only one electron gun, the range in which the beam diameter can be narrowed down to several hundred Å and scanned is several tens.
There is a problem that it is difficult to grow many structures at once because the diameter is as small as several 100 μm.

The present invention has been made in order to solve the above problems, and the size of the entire reactor is small, the flow control of the source gas is easy, and the vapor phase growth of many structures can be performed at one time. An object of the present invention is to provide a line excitation vapor phase growth apparatus and a vapor phase growth method.

[0005]

In order to solve the above problems, the apparatus according to the present invention is characterized by using a micro electron beam irradiation apparatus composed of a semiconductor emitter of a cold cathode. The electron beam irradiation apparatus is formed by stacking an electrode layer on a semiconductor substrate on which a conical emitter is formed with an insulating layer interposed therebetween, and opening an upper portion of the emitter.

Cone-shaped emitters are typically contoured with a diameter of 4-8 μm and a height of 4-8 μm. In addition, one or more conical emitters can be formed on one semiconductor substrate surface by etching a semiconductor substrate and used. The electrode layer is for accelerating and focusing the electron beam and may be used alone, or two or more may be used through the insulating layer.

Irradiation with an electron beam can be carried out by applying a voltage of usually 0.1 to 5 KV between a conical emitter (cathode) and an electrode layer (anode) to generate an electron beam. Further, the electron beam irradiation apparatus of the present invention is arranged so as to face a semiconductor substrate (growth substrate) arranged in the electron beam excited vapor phase growth apparatus when performing vapor phase growth. Further, the growth method according to the present invention performs the growth in the growth apparatus according to the present invention while constantly or temporarily irradiating with an electron beam.

[0008]

According to the present invention, it is not necessary to provide a large space for arranging an electron gun in the growth apparatus by using the micro electron beam irradiation apparatus from the emitter of the cold cathode on the semiconductor substrate, and the flow of the material gas can be controlled. It will be easy. Moreover, since a large number of electron beams can be generated by providing a plurality of emitters, a large number of fine structures can be formed at one time.

[0009]

Embodiment 1 An embodiment of the present invention will be described with reference to the drawings. Shown in Figure 1
As described above, the crystal growth apparatus of the present invention is based on the MOCVD apparatus.
I have to. This device is in the reactor 1 where the growth takes place.
Susceptor 3 with growth substrate 10 mounted on it, source gas flow
Flow channel 6 for controlling the electron beam, and an electron beam generator
2a and a terminal 2b for fixing it and applying a voltage are provided.
It has been burned. The electron beam generator 2a is shown in FIG.
As shown in (b), a circular resist is formed on the Si substrate 20.
Isotropic etching with KOH using a mask,
A conical protrusion 21 is formed. SiO2 leaving mask₂
Insulating film 22a, tungsten electrode 23a, SiO ₂Insulation
A film 22b and a tungsten electrode 23b are sequentially stacked to form a register.
Lift off the mask and complete.

Next, production of a quantum box using this device will be described. As shown in FIG. 1, a GaAs growth substrate 10
Is heated to 300 ° C by the heater 5, and AsH ₃ gas, TM
A fine structure was grown while constantly applying an electron beam while flowing A gas and TMG gas. At this time, the internal pressure of the reactor was reduced to 1 × 10 ⁻⁶ torr by the turbo molecular pump 7. An example of the growth layer is shown in FIG. GaAs growth substrate 1
A with a diameter of about 100Å corresponding to the diameter of the focused electron beam
l _0.3 Ga _0.7 As (layer thickness 30Å) 11, GaAs (3
0Å) 12 and Al _0.3 Ga _0.7 As (30Å) 13 were grown in order to form a quantum box.

However, the electron beam irradiation device 2a is
Voltages V ₁ and V ₁ + V ₂ are applied between the Si substrate 20 and the tungsten electrodes 23a and 23b, respectively. Si
The substrate 20 becomes a cold cathode, and the tungsten electrodes 23a, 2
3b serves as an anode. The electric field between the electrodes is concentrated on the conical projection 21 of the Si substrate, a high electric field is generated, and the electron beam 4 is emitted. That is, the protrusion 21 becomes a field emission emitter for electron beam emission. Two positive electrodes 23a and 23b
Also has a function as an electron lens, so that the electron beam 4 emitted from the emitter is accelerated and focused by a high electric field and irradiated onto the growth substrate. The applied voltage is V ₁ = V
₂ = 1 KV, the focused beam diameter is 100Å.

Example 2 As shown in FIG. 4, production of a multi-quantum box using a vapor phase growth apparatus modified from the MBE apparatus will be described. This apparatus comprises a susceptor 3, a heater 5 for heating, electron beam generators 2a and 2b, growth raw materials As, Ga, Al (51 to 53), and a shutter 9 in a chamber 1'made of stainless steel.

FIG. 5 is a perspective view of the electron beam generator of this apparatus. The electron beam irradiation devices 2a and 2b are used in the first embodiment.
It is characterized in that a large number of field emission emitters using Si protrusions similar to the above are formed in an array. Insulating film 2
The configurations of the electrodes 2a and 22b and the electrodes 23a and 23b are the same as those in the first embodiment.
Is the same as. The electron beam irradiation devices 2a and 2b irradiate the growth substrate 10 with a multi-focused electron beam having a beam diameter of 100Å. The growth substrate is GaAs, As,
Growth was performed by making Ga and Al into a molecular beam and flying.

First, while the substrate temperature is set to 200 ° C. and the growth substrate 10 is irradiated with the multi-electron beam, Al _0.45 Ga is formed.
_0.55 As (Layer thickness 40Å) 31, Al _0.15 Ga _0.85 As
(35Å) 32 is grown, then the growth temperature is 600 ℃
Al _0.45 Ga _0.55
As33 was formed in normal MBE mode. The grown layer structure is shown in FIG. This structure is Al _0.15 Ga _0.85 As layer 3
2 has a multi-quantum box structure in which many Al _0.45 Ga _0.55 As layers 31 and 33 are embedded. Example 3 As shown in FIG. 7, compared with the device of Example 1, a high frequency (R) was used instead of the heater 5 to heat the susceptor.
F) Vapor growth is performed by an apparatus using a heating coil 5'and a nozzle 6'in place of the flow channel 6.

The nozzle 6'is made of Group III raw material TEG, TE
A, TMI, Group V raw materials AsH ₃ , PH ₃
And H ₂ are provided separately. This device alternately supplies group III and group V raw materials from a nozzle to enable atomic layer (ALE) epitaxy. The details of the electron beam generator 2a are shown in FIG.

The electron beam generator 2a is of a multi-beam type as in the second embodiment, but the electrode 23b is separated for each emitter and different voltages can be applied through the terminals 24a to 24d. ing. Since the electric field applied to each emitter can be controlled individually, it becomes possible to emit electrons from only a specific emitter. Growth was performed in the ALE mode while assisting with an electron beam. First, the GaAs substrate 10 (200 ° C.) was irradiated with In while being irradiated with electron beams from all emitters.
_0.5 Al _0.5 P41 10 atomic layer, In _0.5 Ga _0.5 P
42 of 5 atomic layers and In _0.5 Al _0.5 P43 of 10 atomic layers were grown. Then, in FIG. 8, the electron emission from the two central emitters is stopped, and the In _0.5 G
a _0.5 P44 for 5 atomic layers, In _0.5 Al _0.5 P45 for 1
0 atomic layer was grown. As shown in FIG. 9, the center two are I
nAlP / InGaP / InAlP configuration, two of the ends are I
nAlP / InGaP / InAlP / InGaP / In
The selective growth of the AlP structure was realized.

[0017]

According to the present invention, since the minute electron beam irradiation apparatus including the emitter of the cold cathode on the semiconductor substrate is used,
It is not necessary to provide a large space for disposing the electron gun in the growth apparatus, and the flow of the source gas can be easily controlled.
Therefore, the semiconductor fine structure can grow with good controllability. Since a large number of electron beams can be generated by providing a plurality of emitters, a large number of fine structures can be formed at one time. Further, by selectively irradiating the electron beam during the growth or temporarily during the growth, selective growth can be performed in various patterns.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a vapor phase crystal growth apparatus produced in an example of the present invention.

FIG. 2 is an explanatory diagram of a vapor phase crystal growth apparatus manufactured in an example of the present invention.

FIG. 3 is an explanatory diagram of a quantum box manufactured in an example of the present invention.

FIG. 4 is an explanatory diagram of a vapor phase crystal growth apparatus manufactured in an example of the present invention.

FIG. 5 is an explanatory diagram of a vapor phase crystal growth apparatus produced in an example of the present invention.

FIG. 6 is an explanatory diagram of a multi-quantum box manufactured in an example of the present invention.

FIG. 7 is an explanatory diagram of a vapor phase crystal growth apparatus manufactured in an example of the present invention.

FIG. 8 is an explanatory diagram of a vapor phase crystal growth apparatus manufactured in an example of the present invention.

FIG. 9 is an explanatory diagram of a layered body manufactured by atomic layer growth according to an example of the present invention.

FIG. 10 is an explanatory diagram of a conventional vapor phase crystal growth apparatus.

FIG. 11 is an explanatory diagram of a conventional vapor phase crystal growth apparatus.

[Explanation of symbols]

1, 1'101 Reactor (chamber) 2a, 2b, 102 Electron beam irradiation device 3,103 Susceptor 4,104 Electron beam 5,105 Heater 5'RF coil 6 Flow channel 6'Nozzle 7 Turbo molecular pump 8 Rotary pump 9 Shutter 10 Growth Substrate 11, 12, 13 Growth Layer (Quantum Box) 20 Si Substrate 21 Protrusion (Emitter) 22a, 22b Insulating Film 23a, 23b Electrode 24a, 24b, 24c, 24d Voltage Introduction Terminal 31, 32, 33 Quantum Structure 41, 42, 43, 44, 45 Quantum structure 51, 52, 53 Cell 111 Filament 112 Cathode 113 Anode 114 Lens

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroshi Nakatsu 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Within Sharp Corporation (72) Masanori Watanabe 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Co., Ltd. (72) Inventor Masaki Kondo, 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Prefecture Sharp Corporation (72) Inventor, Tadashi Takeoka 22-22, Nagaike-cho, Abeno-ku, Osaka City, Osaka Prefecture, Sharp Corporation ( 72) Inventor Saburo Yamamoto 22-22 Nagaike-cho, Abeno-ku, Osaka City, Osaka Prefecture

Claims (3)

[Claims] 1. An electron-beam-excited vapor phase epitaxy apparatus having a built-in micro electron beam irradiation apparatus including a cold cathode semiconductor emitter. 2. The electron beam excited vapor phase epitaxy apparatus according to claim 1, wherein a plurality of cold cathode semiconductor emitters are formed. 3. A vapor phase growth method for growing a semiconductor layer while irradiating an electron beam onto a growth substrate during or during the growth in the process of growing in the growth apparatus according to claim 1.