JPS6053012A - Method of epitaxially growing iii-v group semiconductor material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD This invention relates generally to epitaxial growth, and specifically to epitaxial structures on selected areas using an ion beam and structures grown by such methods.

Modern semiconductor technology relies on methods for growing multiple high quality organic layers, eg, on a substrate or other epitaxial layer. The layer must have few residual impurities, i.e. undesirable impurities and carrier traps as well as structural imperfections. Accordingly, several methods have been developed to grow such epitaxial layers. The layers may consist of elemental semiconductors such as silicon or kermanium or binary, ternary or quaternary semiconductors of the 111-V or IJ-Vl groups.

The first method developed and resulting in a high degree of perfection for the formation of III-V compound semiconductor materials was liquid phase epitaxy (LI). Although this method has been well developed to date and is fully capable of fabricating many types of epitaxial layers and devices comprising at least one such layer, it is not without limitations.

For example, LPE typically transfers a substrate from one melt to another with epitaxial growth occurring in each melt.
, <lj to move to scatter and force is ・bi・an. d
! Typically, the composition changes and therefore care must generally be taken to prevent undesired migration of melt components from one melt to another. Although this limitation may be overcome by using and manipulating the device deeply in /4EH, other limitations appear to be more fundamental and overcome only in speed.

For example, it may be impossible to fabricate extremely thin layers with a thickness of 20 nm or less using this technology.
Usually difficult.

It is difficult to reproducibly grow smooth layers even for very thin layers below 1100 nm. It is also difficult to produce.

Because of these and other limitations, among other reasons, other methods have been developed for the growth of III-V compound biomass. Among these techniques, the one that currently appears to be the most successful is molecular beam epitaxy (M
B E ) There is. Regarding this method,
John R, Art
+r Jr. ) on October 26, 971, the United States! 1. ````1〆``No. 3015.931, 51
It is described in detail. In MBE, the desired III
The thermally evaporated beam is heated to a temperature sufficient to evaporate the A2 mixture, and the thermally evaporated beam causes epitaxial growth.
＼Aimed at the board. The substrate is already kept at a temperature high enough for surface diffusion and epitaxial growth to occur (but low enough that the probability of interest being adsorbed to the surface is not adequate). The beam has a cosine-like separation distribution, and the basic technique is supplemented with other techniques such as substrate rotation and rotation, and a large-diameter, highly compositionally homogeneous plate 1 (plate-1) is used. j'J
'--Epitaxial layer grows. Furthermore, due to gamma ray epitaxy, the shape of the middle molecular layer and the epitaxial layer of the C. [[Formation between W with formation and Taupin tree transformation becomes possible =.

The beam used in molecular beam epitaxy is generally electrically neutral. However, beams of non-thermally charged particles, or ions, are used in at least some semiconductor epitaxial growth techniques ((
It has become. By using non-thermal ions, it is possible to lower the substrate temperature during growth, since the kinetic energy of the deposited particles promotes surface diffusion. Ion beam epitaxy technology Regarding the formation of InSb thin films by
The Hakiam Society Off Japan
rnal of tbe Vacuum 5ociet
yof Japan) 20, 241, 21I 6, July 1977, 7. ). The technology is
Ionized In and u:sb particles are described. The ions were applied with a constant voltage of 1000 volts or more applied to the substrate. Not specifically stated or growth over a uniform area revealed. However, the composition: li! For control purposes, flash evaporation was used. In other words, since the deposited J, Hakama's sho, and Ru are pre-medium...1] In and SB powder particles,
By flash evaporation! 1ill 1iIll.

Is it important to measure your hands in advance for both In and sb?
This is necessary because it has an Ld load and therefore a high coefficient of adhesion at the substrate surface. Therefore, the deposited layer is In
or sb may be incorporated into the layer in excess, resulting in a completely stoichiometric composition.

Using ion beam epitaxy
ue (100) or silicon Si (100)')IA
For epitaxial growth of silicon on :L Si(] ] ] ) substrates, see Applied Physics Letters.
ters), 4], pp. 167-169, July]
511, 1982 (・ro. stated ℃
・The filtration method uses silicon ions with an energy of 50 to 1 (I) eV, and 3oO/I:(・
Epitaxial silicon can be performed at a di-temperature of 900 K i; The growth of thin high-quality silicon layers was reported.

However, depending on this method, the formation of only elemental semiconductors (
is possible.

As should be clear from the foregoing, molecular beam epitaxy is generally not a selective area growth technique. This is because the molecular beam is incident on the all-crystalline substrate and the beam (4) covers the entire substrate surface. ;
A modified version of the basic molecular beam epitaxy technique described in ', r], -') has been developed. However, these technologies require, for example, appropriate substrate preparation steps, which add to the complexity of the process.

For example, December 2:3, 1975 William Charles Harami (Wi I) iam charle
sBallamy) and Alfred Y'i Cho]! See Grant No. 3982092. US%'
The method described in Ico'1-3'J82092 involves forming an amorphous insulating layer on a III-V substrate and removing selected portions of the layer to expose the underlying crystalline insulating material. By forming a patterned substrate, a planar isolation device is formed. These steps are also performed outside the M 13 E growth chamber. The substrate is also MB-patterned for material deposition by MEE.
Moved to member E's room. Single crystal grains grow only on the exposed portions of the plate. Other selective area growth techniques are known, such as mechanical shadow mask techniques.

In the epitaxial formation process, the ion beam is 11111.・It leaked too much.

The analogy is Applied Physics Letters (Ap
Plied Physics Letters) 4
0.

fi 8 (pages 5-688, April 15, J982) describes the use of high-energy ion beams in the fabrication of silicon.

Amorphous silicon is first deposited.

A high energy arsenic ion beam of approximately 2.5 M e V is then directed onto the amorphous silicon layer. The resulting heating causes recrystallization of the amorphous silicon, and impurity arsenic atoms from the ion beam enter replacement positions within the crystal lattice.

Selected area epitaxial growth uses ion beam epitaxy, in which a first beam consisting of group 1 particles is scanned over a selected area with a wide field of view, and a second thermal beam consisting of V film particles is applied to the selected area. By flowing over a wide area,
I get caught.

The first beam consists of ionized particles during a portion of the transit time between the source and the substrate, during which time the beam is directed to the desired substrate area.

The second beam may be neutral, such as ionized by conventional thermal evaporation, or it may be ionized. The growth rate will depend on the group III particles on the substrate surface, thus selective area growth will be obtained. The beam of deuteron particles may consist of aluminum, potassium or indium particles (,V)M and -m may consist of film particles such as υ, phosphorus or antimony. If necessary, II.
The first beam of Group I particles has a desired energy of 1! I, after the beam is scanned in the desired direction,
It may be neutralized.

In another embodiment, the substrate is flushed with a second Group 111 particle beam, and molecular and ion beam epitaxy occur simultaneously on different substrate regions.

In yet another embodiment, multiple ion beams are simultaneously incident on the substrate at the same or different substrate regions 4). In addition,
Ion-beam epitaxy according to ``Non-explosion'' may be used for growing compound feeds, and may also be used to
One or more constituent elements 7) 2) have a significantly lower layering coefficient than other constituent elements at a growth temperature of -t6°C.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 1. An apparatus suitable for carrying out the invention is schematically shown in FIG. The apparatus includes at least one ion beam source for group I elements designated 1030, ion source 103;
Means for scanning the zero ion beam consists of group 1 ejection ovens marked 1040 and 1020. The ion source 103o further includes means for accelerating particles,
The analogy consists of an acceleration can. These elements are chamber 1
000 and the chamber is subjected to a sieve vacuum by means of a pump 1050, i.e. at least
Pa (10'Torr), preferably 7 or at least 133
．． 322X]0'Pa (10"L"orr). A particle beam from the oven and ion source is directed at a substrate 1010 located within a chamber 1000 at t□, not shown schematically by the arrow.

The ion beam sources used and the means for scanning the O ion beam are well known to those skilled in the art, for example from Applied Physics Letters.
ed J] hysics Letters): U4,
310-312, 1979. Group 111 elements are introduced into the ion beam source. By scanning or deflecting means, the beam can be scanned to any point on the substrate. That is, it can be directed to any point on the surface of the two-dimensional substrate. The points come together to form a large area, such as a selected region within a substrate. The means for deflecting may be, for example, any conventional electrostatic or electromagnetic deflection means. Such means are well known to those skilled in the art and need not be described in detail. Those skilled in the art will readily recognize that the ion beam may be focused. In addition, if it is not necessary, the ion beam may be deflected in the desired direction after the ion beam is accelerated, and then deflected in the desired direction.

At least one blowing oven for group elements is a conventional blowing oven using a step of resistively heating the oven to the evaporation temperature.

Multiple ovens may be used for Group I elements.

Group V elements are injected into the ejection ovens. This means that the entire substrate, or only an essential part of the substrate, is exposed.If molecular and ion beam epitaxy are to be performed at the same time, the Group 1 elements should be placed in a separate ejection oven.

It is desirable to improve the adhesion coefficient of group elements during formation.
・If so, add group ■ elements as well, and calculate it to −C℃・.

■ [Important ion beam parameters include the following: current, beam size, beam energy,
is the scanning speed. In general, the beam current should be as large as possible because this parameter essentially determines the rate of epitaxial growth, allowing faster growth than the '1L current. A typical beam 41L flow is between 5 μA and about 150 μAσ RU, box 1]j. The size of the 4-person pattern, which is essentially one-dimensional and one-sided, is determined by the size of the ion beam σ. The typical ion beam diameter at the substrate surface is In the case of Renaro ion beam epitaxy, the diameter is on the order of a few microns. Smaller diameters can be obtained at low ion beam energies, but even small ?lf. At higher energies, for example 1 Smaller diameters below μm easily (4) leak.

The shape is formed by either an r-11-scan or a repeating scan with a .degree. shift. The beam energy is typically about 10 cV' per beam; The upper limit is determined by the beam particles being able to cause almost no damage to the substrate.The lower limit is determined by the ion compatibility However, within this range, as the accelerating voltage force 11 decreases, the beam can be easily focused on a small beam, making it possible to draw smaller shapes. The scanning speed will depend on the desired thickness in the growth direction of the silage epitaxial growth (starting with the ion beam), since the smaller the scanning speed, the faster the scanning speed will be. The velocity of the particles in the ion beam results in a thicker layer in the growth direction. Another important growth parameter is the substrate temperature. The energy G-contributes to the substrate's anti-caloric properties and increases surface diffusion.Thus, the substrate is generally exposed to normal temperatures in MBE.
There is no need to heat it to a high temperature.

Desired group 1 and group 2 elements are placed in a conventional ejection cell and ion deposition oven, and placed in the growth chamber together with the substrate.

The substrate has a lattice constant of r#-ZIII-V such that there is a small lattice match with the desired epitaxial layer.
consisting of group compound semiconductors. After converting the board to /'4E using the technique of engineering J1-1, YJ133.32
It is evacuated to a pressure of 2X]0-Il Pa (10-1 Torr) and heated to the desired temperature in the oven and in the oven. The value required to achieve the desired flank height of 111 and group V elements on the substrate surface can be determined.

Within the ion beam source containing Group 1 elements, the oven should be heated to a temperature sufficient to ensure bath melting of the insert. The particle flux intensity from the ion source is controlled by the magnitude of the preparation voltage and accelerating voltage. The beam of liquid particles is scanned over the substrate surface, while the beam of Group I particles floods the surface at the same time. The Group III particle density at the surface controls the rate of ion beam initiated epitaxial growth.

Other embodiments are also possible. For example, a heat beam consisting of group IIJ particles may also flood the substrate. Then,
Molecular beam and O/ion beam epitaxy proceed simultaneously. If the molecules and the ion beam are made of the same group III element, then the two elements or the binary material A; The ternary materials are the two forces! 11i
('I grows in the area where only the molecular beam is incident. By using multiple molecular beams or ion beams, binary, ternary, and quaternary materials can be grown. It will be readily appreciated that the growth of selected chain acids can proceed simultaneously; for example, a thermal beam of two or more Group V particles may be used.

Several desirable contributions of ion beam epitaxy according to the present invention are apparent. In particular, in order to obtain the desired beam size, a highly directional ion beam can be made incident onto any selected substrate area by appropriate defocusing or focusing, and then electrostatic The beam may be deflected either targetedly or electromagnetically to produce the desired pattern.

Growth rate is precisely controlled by both beam scanning speed and beam current. By varying these parameters during the ion beam initiation process, the rate of both growth and lateral geometry, along with the chemical composition of the epitaxial line, can be made very dense.

Because the ion beam carries a charge, it can be used instead of the mechanical shutter normally used in molecular X'ij epitaxy.
It can be quickly turned on and turned off by electrostatic or electromagnetic means.

This makes it possible to create a very steep compositional change.

Examples of some structures in which Pl is lengthened by the method of the present invention are shown in Figures 2-8. Figure 2 shows the board 1,
a first epitaxial layer 3 having a first conductivity type;
A buried hetero'tM laser is shown comprising a second epitaxial layer 5 having a conduction type of 1 and a plurality of active stripes 7. - In the example, the device is an n-type GaAs substrate, an n-type ANOXC;a, -xAs first layer 3, p-type AtX Ga, -XAS second layer 5 and QaA
It consists of 1 stripe and 7 stripes. A1. XGa1
XAS layers 3 and 5 are grown by conventional M 131. technology. After growing the active stripes 7 layer 3, 13. let The stripes L-) are grown by scanning a Ga beam in a rask to form an array of GaAs stripes.

FIG. 3 shows a structure consisting of a one-dimensional conductive channel for an electronic device. The term ``'-dimensional'' means that the dimensions of the formed shape in two directions are sufficiently small so that the carrier nine key level is quantized.

The structure consists of a substrate 31 , a plurality of epitaxial layers 33 , 35 , 37 and 39 having a first conductivity type and a plurality of one-dimensional tubes 301 . The -dimensional channels, or tubes, are grown by ion beam epitaxy, and the layers surrounding the channels are grown by MBE, as described above. The channel may be conductive. A one-dimensional array of highly conductive channels, dregs in the tube, is formed as carriers, electrons or specie, migrate from the n-type or p-type semiconductor layer into the undoped tube. As will be recognized by those skilled in the art, No. 5 33.3
5, 37 and 0.39 may be either 1] or I), and the tube will contain one-dimensional electrons or hole dregs within the ItfJU mother (().

FIG. 4 shows a field-effect transistor with one-dimensional mobility '1[+ and field effect transistor '1-. Device ti'f (source, train and O
η of the gate electrode. Regions 41, 0 and 45 are semi-insulating semiconductors, while regions 42, 43 and 44 consist of source, gate and train regions, respectively. The one-dimensional 'cji particles or hole dregs labeled 401 form a high mobility conduction channel between the source and drain regions.

- Dimensional tubes do not need to be flat.

Another 'field effect transistor with a -dimensional channel is shown in FIG. The transistor is based on 51:
It also comprises a first epitaxial layer 53 having a first conductivity type; source, gate and train electrodes 55, 56 and 57, respectively. The source and drain regions are connected by an undoped-dimensional naeuf 59.

FIG. 6 shows a structure consisting of a substrate 61 and a three-dimensional array of electron or hole pockets 63. The pockets form a three-dimensional structure with a periodicity that can be easily varied. Pockets can be created by modifying the technique used for one-dimensional tubes so that the ion beam is periodically incident on the substrate long enough to form the desired pockets.
It is formed.

Ion beam epitaxy is also useful for growing integrated optical devices. For example, FIG. 7 shows a laser structure with multiple active regions resulting in a single waveguide, which is conveniently fabricated by ion beam epitaxy. The structure includes a substrate 71, a first epitaxial layer 73 having a first conductivity type, and a second epitaxial layer 7 having a second conductivity type.
5 and a plurality of active stripes 701 coupled to a waveguide 710 at the interface between layers 73 and 75. Grow active stripes by ion beam epitaxy proceeding simultaneously with molecular beam epitaxy. Since both ion beam epitaxy and consonant beam epitaxy are carried out simultaneously, the composition of the waveguide portion depends on the growth rate of the ion beam epitaxy or the growth rate of the active stripe during the growth of the waveguide portion. Ram: Shi, l fortune 1
<1- You can change the composition of the stripes.

FIG. 8 shows another application of ion beam epixiety according to the present invention in the fabrication of integrated optical devices. The structure also consists of a substrate 81, a waveguide 83 and O-devices 85 and 87. Curved i, (F wave path 83, optically device 85
And 8 phi...combine sazero. From the diagram. Thus, waveguides having essentially the shape of . . . , .

If the ion beam is significantly exposed to the array energy, material removal can occur.

M 131! When I woke up 1), I saw an ion beam and a different Sei 1 (Yusong 1 and Fear 1).
The road 1/1 i bh' old formation is 7[1 rip, bivalent area of the ion beam. and 7J24Ti Schiff, which will occur in the °C region. In addition, scanning? Steps 14 and 14 may be performed at the same time.

As is easily recognized, other σ) interest systems can also be used. For example, there are other σ group III-V compound semiconductors, metals, semiconductors, and superconducting wood-C.
All devices described as having -dimensional channels can be formed to larger dimensions if the carrier energy level is desired to be quantized to lower quantum numbers. good. Teno chairs other than those described here may be made. For example, -Next, you can make a quantum well laser.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically representing a vehicle suitable for carrying out the present invention, and FIG. 21 and FIG.
FIG. [Explanation of symbols of main parts] Semiconductor substrate 10°FIG, / FIG, 2 FIG, 3 FIG, 4 FIG, 5 FIG 6 FIG. FIG.

Claims (1)

[Scope of Claims] 1. irradiating at least one thermal beam of particles onto at least one selected area of a semiconductor substrate, comprising: In a method for epitaxially growing an IH-V group semiconductor material, at least one beam of group 111 particles is scanned over the selected area, and a small number (at least one beam) of group V particles is applied to the wide area. Flood the heat beam and, if necessary, flood the heat beam with at least one group 1 particle.
A method for epitaxially growing an Ill-V group ξI material. 2.1'l In the method according to claim 18'1, whenever the scanning beam of group (1) particles is at or above 2°C, the particles may be composed of similar or different elements. A method for epitaxially growing IJI-V group semiconductor paulownia wood, which has the advantage that it can be formed. 3. In the method according to claim 1, whenever a plurality of beams of group particles fill the wide area, the particles in such beams are composed of similar elements. A method for the pitaxial growth of ■-■ semi-group semiconductors characterized by the fact that they can also be composed of different elements. 4. The method according to claim 1, characterized in that at least one of the scanning beams is formed by turning on the Illlln particles.
A method for epitaxially growing an I-V group semiconductor material. 5 In accordance with the method described in 1. 2 of the patent claim, applying the Group III beam in the /L beam at a voltage of 12, IO volts or more: 500 volts or less: j4i For use in epitaxial growth of V-family materials, which are characterized by being produced. 6. The method of claim 5, wherein the voltage is 2000 volts or more. 7 q'! iClaim 6, Article θmi: 1
11.1-V family m'fi 4. G, the scanning process and the overflowing process are used sequentially. :! ,]1:
How to epitaxially grow 1. H.71:1'' 1. The method according to claim 5, characterized in that the voltage is 2000 volts or less.
A method for epitaxially growing a II-V group half-domain monolithic material. 9. A method for epitaxially growing a Group III, -V semiconductor material, as claimed in claim 5, characterized in that the overflowing process and O-scanning steps occur simultaneously. 10. The method according to claim 5, characterized in that the scanning is by electromagnetic means.
A method for epitaxially growing a group V semiconductor A material.