JP3404815B2 - GaInAs two-dimensional electron Hall element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION The present invention relates to a semiconductor device comprising GaInAs.
Utilizes two-dimensional electron gas revealed by conductor heterojunction
Related to the GaInAs two-dimensional electron Hall element,
It relates to increasing the sensitivity of a Hall element. [0002] 2. Description of the Related Art A magnetic field is detected and its strength, that is, the magnetic field strength is detected.
A so-called magneto-electric conversion element that generates an electric signal in accordance with
One known element is a Hall element. This
The Hall element has a Hall effect when a magnetic field is applied.
E generated by the movement of electrons in known semiconductors
Is a type of magnetic sensor that uses the voltage of
Rotation detection, position detection sensor,
Stylus for measuring magnetic field strength in addition to current sensor
(Probe). [0003] Semiconductor materials for Hall element use include silicon.
Elemental semiconductors such as concrete (Si) and germanium (Ge)
, Indium antimonide (InSb), indium arsenide
Elements such as indium (InAs) and gallium arsenide (GaAs)
Elements belonging to Group III of the Periodic Table and also Group V
III-V binary compound half compounded with element belonging to
Conductors are also used. However, conventional compound semiconductors
If you look at the Hall element, depending on the physical properties of the semiconductor used,
There are advantages and disadvantages in the characteristics of the rule element. For example, Ga
The Hall element made of As is a band gap of a GaAs semiconductor.
The temperature change of the element characteristics is small due to the relatively large
However, conversely, because the electron mobility is somewhat low, the product sensitivity is In
The drawback is that it is lower than the Hall element composed of Sb.
You. On the other hand, the InSb Hall element is an InSb semiconductor bump.
Temperature gap of characteristics is large but high due to low gap
This has the advantage that product sensitivity can be obtained. Recently, precise rotation control of automobile engines has been performed.
The need for precision sensing technology in high-temperature environments
Have the ability to output high Hall voltage and increase temperature
High-performance Hall element that suppresses changes in element characteristics due to heat
Has been requested. Where the Hall voltage is semiconductor
It depends on the Hall coefficient of the material.
Output voltage is high. Also, this Hall coefficient is
It increases in proportion to the electron mobility of the body material. Therefore, high
To obtain a Hall output voltage, that is, a high-sensitivity Hall element
Use a semiconductor material that exhibits high electron mobility to obtain
Need to be [0005] For this reason, studies on the physical properties of semiconductor materials are also required.
In recent years, the so-called 2
By two-dimensional electron gas
A Hall element utilizing the high electron mobility characteristics that has been revealed
(Eg, R.C.GALLAGHER and
W.S. CORAK, Solid-State Electronics, Volume 9 (19
1966), pp. 571-580, Tokuhei 3-2503
5). However, such a two-dimensional electron has been
Conductor and silicon dioxide (SiO_TwoAt the heterojunction interface with
This so-called Si-MOS
(Metal-oxide-semiconductor) expressed by the structure
Hall elements using two-dimensional electrons have already been used in the 1960s
Reported midway. Further, two-dimensional electrons having the above-mentioned MOS structure are used.
Of binary compounds such as GaAs and InP
III-V compound semiconductors in the same way as the body
Gallium aluminum arsenide (Al_X
Ga_1-XAs) and gallium indium arsenide (Ga_XIn
_1-XHeterojunction with ternary mixed crystals of compounds such as As)
Also, a method for forming a two-dimensional electron gas has been known.
I have. Heterojunctions based on such known combinations
For obtaining two-dimensional electron gas formed by
The intrinsic semiconductor and the higher bandgap
Consisting of N-type semiconductor with gap (band gap)
You. For example, AlGaAs is an N-type semiconductor and GaAs is
Heterojunction for obtaining two-dimensional electrons as intrinsic semiconductor
Combinations are already known and based on such known combinations.
Using two-dimensional electron gas formed by heterojunction
Semiconductor devices include high electron mobility field effect transistors
It has been realized as a star (Japanese Patent Publication No. 59-46425,
See Japanese Patent Publication No. 59-53714). In such a combination, other Ga_x In_1-x
Heterojunction between As (x represents composition ratio) and InP
It has been known. Furthermore, the intrinsic half forming a heterojunction
The conductor is not limited to the above compound semiconductors,
Elemental semiconductors such as Ge (Ge)
Two-dimensional electrons are obtained by forming a heterojunction with s.
Various other semiconductor materials for obtaining two-dimensional electron gas
Is already known, but the two-dimensional electron gas
The important thing to form is to make electron affinity different from each other
To combine semiconductors (for example,
53714, JP-B-59-46425, USP 4,16
3,323). Semiconductor materials having such different electron affinities
Simply forming a heterojunction based on the combination of
High electron mobility characteristics can be obtained stably
Not necessarily. To explain the reason, the above-mentioned AlG
Schottky using heterojunction between aAs and GaAs
-A junction type high electron mobility transistor is taken as an example. This
Electron mobility is the transconductor
Important transistor characteristics such as impedance and noise figure
Is a factor. However, simply forming a heterojunction
Alone does not provide high electron mobility stably. this is
The presence or absence of two-dimensional electrons depends on the steepness of the heterointerface
Although it depends on the state, etc., even if there are two-dimensional electrons,
High electron mobility characteristics are hindered by factors such as electron scattering.
This is because there are cases where For this reason, electron affinity
GaAs with high power and AlGa with lower electron affinity
Normally undoped AlGaAs at the hetero interface with As
Inserting layers has been done. This non-added layer is generally
Is called a spacer layer and is made of AlGaAs / Ga
Not limited to the As heterojunction system, but AlInAs / GaInA
s heterojunction high electron mobility transistors
It is also provided in the base material. However, by inserting a spacer layer,
To prevent high electron mobility characteristics of two-dimensional electrons such as electron scattering.
Although the effects of harmful factors can be reduced, the sheet carrier
Concentration and electron mobility are sensitive to the thickness of the spacer layer
On the contrary, precise control of the thickness of the spacer layer is required.
Results in adding new complexity to the thin film growth process.
Was. [0011] SUMMARY OF THE INVENTION High electron mobility transistors
Not only for star devices, but also for Hall elements that use two-dimensional electrons.
The situation is the same even if the spacer layer is inserted.
Higher electron mobility characteristics have been obtained. example
For example, a heterojunction composed of AlGaAs and GaAs
Hall elements that use two-dimensional electrons
AlGaAs is used as a spacer (electronic information
IEICE Transactions, Vol.J70-C, No.5 1987, p.p.758-76
3 and Proc. Of 6th Sensor Symposium, Tokyo 1986 p.
p.547-550). In addition, the connection between GaInAs and AlInAs
High resistance Al
InAs can be inserted into the hetero interface as a spacer
(Technical Digest of the 11th Sensor
Symposium, 1992 p.p.79-82). In any case
The layer thickness is less than 10 nm, usually about 2-5 nm.
It is a thin layer and has high electron mobility characteristics by two-dimensional electrons
In order to stably control such an ultra-thin layer,
It requires dense and sophisticated growth technology,
The desired high electron mobility characteristics can be obtained by controlling the layer thickness.
Whether or not a high sensitivity hole by two-dimensional electrons
The result was that the yield of the device was affected. Further, the heterojunction between GaInAs and InP
To explain mainly the application to the combined Hall element,
In a terrorist combination, Ga_x In_1-x As for N type half
A heterojunction using InP as an intrinsic semiconductor
The two-dimensional electron gas assumed to be brought to
Hall elements with high sensitivity have also been proposed (see
0-198870). More recently, a heterojunction has been formed.
The combination is the same, but conversely Ga_x In_1-x
Let As play the role of intrinsic semiconductor and make InP N-type
High sensitivity Hall elements as semiconductors have been newly realized.
(For example, 53rd Applied Physics Autumn 1992
Conference Proceedings No. 3 (1992 Japan Society of Applied Physics
Published), Lecture No. 16a-SZC-16, 1078
page). This new GaInAs Hall element has a characteristic temperature
The change is relatively small and the electron mobility at room temperature is extremely high.
Reported to be Unprecedented for High Product Sensitivity Due to High
Have been. The new high-sensitivity Hall element is a conventional high-sensitivity Hall element.
Using high electron mobility due to two-dimensional electrons
What is s / GaAs heterojunction Hall element?
Is different from GaInAs directly without the need for a conventional spacer.
InP is heterojunction. I don't need this spacer
High electron mobility characteristics with simple and convenient heterojunction structure
Insert a spacer layer if it can be obtained with good reproducibility
The complicated and complicated process of
Eliminates the complexity of manufacturing thin-film matrix materials for child applications
In addition, the manufacturing cost of this new highly sensitive Hall element
It is expected to have the advantage of avoiding the rise. However, such a GaInAs / InP
Take advantage of the high electron mobility characteristics exhibited by the heterojunction system.
Even in the high sensitivity Hall element used,
Desired high sensitivity characteristics are not always obtained. It is this
Causes of high mobility in heterogeneous systems
Not yet determined, required for stable formation
Requirements are not yet clear.
You. Therefore, contrary to the conventional high sensitivity Hall element, Ga
_x In_1-x Let As play the role of intrinsic semiconductor,
Hoe directly heterojunction with InP without the intervention of a pacer
Also, in the case of a liquid crystal element, it is necessary to specify high electron mobility characteristics.
Has an unprecedented advantage in the laminated structure that no
However, a GaInAs / InP heterojunction Hall element
The problem is that high sensitivity characteristics cannot be obtained stably in
Existed. On the other hand, a strained layer is interposed at the interface of the hetero junction.
In view of the technical methods for obtaining high electron mobility characteristics,
The realization of high electron mobility field effect transistors
Has reached. This Ga_x In_1-x With an As strained layer interposed
High electron mobility field effect transistors are usually
Called domorphic type transistor, low noise signal amplification
It is used as an element for use. For this kind of transistor
When describing the constituent elements of the base material,
Ga with elastically confined strain on As layer_x In_1-x As
Heterogeneous product with deposited layer and further deposited AlGaAs layer
It is very common to include a layered structure. This GaAs
Ga deposited on the s layer_x In_1-x In the As layer, strain
The film thickness is naturally limited because it is necessary to confine
Usually, it is set to about 10 nm. In this way,
Ga_x In_1-x High electron transfer using a strained layer made of As
In the structure for obtaining the mobility characteristic, the strain is Ga_x I
n_1-x As is present throughout As,_x
In_1-x As precise control of the thickness of the As layer is required
In addition, to obtain high electron mobility characteristics, GaAs or Al
Reduced steepening of heterojunction interface with GaAs and other materials
Must be achieved in the thin film growth process.
At present, complicated operations are involved. However, a transformer using a strained layer as described above is used.
Although the resistor is well known, it has a laminated structure including a strained layer.
Sensitivity of Hall elements using two-dimensional electrons obtained
No attempt has been made to achieve
The strain layer present inside the formed semiconductor layer
The characteristics, especially the effects and even the effects on high sensitivity, are still clear
It is also true that the two-dimensional electron
While it is expected that child mobility can be obtained,
Of a new Hall element with high sensitivity as a
While expected, the development of such highly sensitive Hall elements
At present, it is not progressing slowly. The present invention has been made to overcome such a situation.
So Ga_x In_1-x 2D by heterojunction with As
High-sensitivity GaInAs Hall element applications with electrons
Is based on two-dimensional electrons
In order to stably obtain high electron mobility characteristics,
Clarify the requirements that the components of the joining material should have, and
GaInAs two-dimensional electron Hall element with excellent sensitivity characteristics
To provide a new way to obtain stable. [0019] SUMMARY OF THE INVENTION The present invention provides an unprecedented feeling of high sensitivity.
Stable GaInAs two-dimensional electron Hall element
For Ga_x In_1-x Heterojunction matrix material containing As
Has no high electron mobility characteristics due to two-dimensional electrons, and
Requirements for stable expression, especially electron transfer
Clarification of the role of the strain layer on the degree
Overcoming the instability of the appearance of two-dimensional electrons in heterojunctions
What you want to do. That is, Ga_xIn_1-x As and
InP or Al lattice-matched with InP_y In_1-y As etc.
By heterojunction with another III-V compound semiconductor
In a two-dimensional electron Hall element using two-dimensional electrons, distortion
High electron mobility due to two-dimensional electrons in the presence of a layer
In order to manifest, Ga_x In_1-x When the thickness of the As layer is 5
The thickness is from 0 nm to 500 nm. Further, Ga_x In
_1-x As and InP or Al forming a heterojunction with As
_y In_1-y III-V compound semiconductor layers such as As
Quantitative analysis of the strain area that should exist inside both layers
The area where the strain exists inside both layers was added to
Ga as the distance from the terror junction interface_x In_1-x In the As layer
In the part, the thickness should be 10 nm or less, and a heterojunction with this
InP or Al_y In_1-y30 for As, etc.
nm to reduce the high electron mobility characteristics due to two-dimensional electrons.
GaInA, which has a high sensitivity than ever before
An S-hole element is provided. Normally, a GaInAs two-dimensional electron Hall element
In order to obtain InP, a high-resistance semi-insulating InP
A single crystal substrate is used. Practical specific resistance of Hall element
Is 10^Four Ω · cm or more, 10⁸ InP single less than Ω · cm
It is common to use crystals as the substrate material.
Crystals are liquid sealed Czochralski (Liquid Encapsula)
ted Czochralski (LEC) method and recently VB (Vertic
al Bridgman method)
It can be easily manufactured. On this InP single crystal substrate, n-type Ga_x I
n_1-x An As (x represents a composition ratio) layer is formed. Normal
Is a buffer layer (buffer layer) of InP on an InP single crystal substrate
It is generally deposited as. This buffer layer
The diffusion of Fe impurities from the InP single crystal substrate.
Effects such as suppressing scattering and propagation of crystal defects.
Hall element to maintain high electron mobility
The advantage is that the high sensitivity characteristic of the above can be maintained. Also, loose
The material of the opposing layer is not limited to InP but may be other materials, for example, AlInA.
Gallium arsenide phosphide lattice-matched with s and InP
III-V compounds such as uranium (GaInPAs)
You can use your body, etc. The above InP buffer layer and Ga_x In
_1-x There is no particular limitation on the growth method of the As layer,
Taxi growth method (Liquid Phase Epitaxial; LPE)
Method), molecular beam epitaxial growth method (Molecular Beam E)
pitaxial; MBE method), metal-organic pyrolysis vapor deposition,
Wauru MOVPE (Metal Organic Vapor Phase Epitax
ial; also called MOCVD or OMVPE
is there. ) Or, alternatively, combining both MOVPE and MBE
The MO / MBE method can be applied. Further, the Ga_x In_1-x Mixed crystal ratio x of As
Is preferably set to 0.37 ≦ x ≦ 0.57.
No. This is because Ga lattice-matched to InP_x In_1-x
As the mixed crystal ratio of As deviates from the mixed crystal ratio x = 0.47,
Ga_x In_1-x The difference in lattice constant between As and InP,
The degree of inconsistency of the elements also becomes remarkable, inducing a large number of crystal defects, etc.
Not only causes a decrease in crystallinity, but also a decrease in electron mobility
The characteristic characteristics of the Hall element and improve the product sensitivity
This can cause a great deal of trouble. The above-mentioned Ga according to the present invention is_x In
_1-x There is no particular limitation on the carrier concentration of the As layer.
However, the high electron mobility characteristics of this heterojunction system
1 × 10 for stable use^Fifteencm^-35 × 10 or more
¹⁷cm^-3Good results are obtained with the following range. Why
If the carrier concentration is 1 × 10^Fifteencm^-3If less than
Input and output electrode ohmic
Causes the instability of the ohmic characteristics and increases the electrode resistance.
This is because instability of the Hall element characteristics occurs. on the other hand,
Ga_x In_1-x The carrier concentration of the As layer is 5 × 10¹⁷cm
^-3When it exceeds, the decrease in electron mobility becomes remarkable and high sensitivity
GaInAs / InP heterojunction Hall element with
It is not a good idea to get it. Next, Ga_x In_1-x As layer and buffer layer
InP or Al_yIn_1-y Heterojunction with As
When forming, provide strain inside both these layers
It is booked that further increase in electron mobility is achieved by
The inventor has found. In addition, the inventor of the present invention
Intensive study from the viewpoint of obtaining stable child mobility
The results show that the region where the strain exists
Ga from the interface of_x In_1-x 10 nm reaching inside the As layer
Within the buffer layer and the area where the strain exists in the buffer layer
Good results can be obtained by setting it within 0 nm.
found. Here, a method for confirming the existence of distortion and the existence of distortion
This is a method for quantifying the width of the
CAT (Comp) using a transmission electron microscope
Osit ion Analysis by Thic
Kness-fringe method (H. Kakibayaya)
shi and F. Nagata Jpn. J. Ap
pl. Phys. Vol. 24 (1985) L90
5). The visual results obtained by this method
To explain the outline of the result, for example, the semiconductor layer-I and the semiconductor
A CAT photograph of the heterojunction with Layer-II shows FIG.
A fringe peculiar to each layer is schematically shown in FIG.
appear. If there is no strain in each semiconductor layer,
This stripe pattern is formed when the semiconductor layer-I and the semiconductor layer-II are joined.
Without bending to the interface where it is, ie the heterojunction interface
It will expand. On the other hand, here, temporarily, the semiconductor layer -I
Assuming that there was strain in the
As a result, stripes peculiar to the semiconductor layer-I as shown in FIG.
The pattern bends near the heterojunction as a result. Obedience
Therefore, the presence or absence of such bent stripes is investigated by the CAT method.
Then, the presence or absence of the distortion can be determined. Also, the bent of the stripes
Distance from the ending heterointerface, indicated by the symbol d in FIG.
Observation with an electron microscope that measures the distance represented and provides it for observation
Correction according to magnification enables accurate detection of areas where distortion exists.
(Akira Sotomura, edited by Electron Microscope Technology)
(Issued August 31, 1989: Maruzen Co., Ltd.), 83
page). A strain is applied to a specific region from the heterojunction interface.
There are several methods for providing
A P layer is grown epitaxially and then Ga_x In_1-x A
In the cooling process during the thin film growth process after depositing the s layer
And properly adjust the cooling rate of the wafer after thin film growth.
This makes it relatively easy to apply strain to Ga_x In_1-x As layer arrangement
Can be introduced into both layers of the InP layer. The inventor is eager
As a result of the examination, it was found that Ga in the MOVPE method_x In
_1-x The typical growth temperature for As and InP thin films is 60
It takes about 20 minutes to cool from around 0 ° C to 200 ° C
That is, when cooling at a rate of about 20 ° C. per minute,
The present invention can be relatively easily implemented by utilizing the difference in the coefficient of thermal expansion between the two materials.
Satisfactory distortion can be present. In addition, InP
After growth of the stratum, Ga_x In_1-x In growing As,
Ga whose composition ratio x is slightly different from desired_x In_1-x As
Is grown with a certain layer thickness to form a hetero interface
After that, Ga with the predetermined composition ratio_x In_1-x Grow As
In the case where Ga_x In_1-x As and In
A strain layer can be present inside a buffer layer such as P.
However, in this case, it has a composition ratio different from a desired composition ratio.
Extremely thick Ga_x In_1-x As is InP and Ga_x In
_1-x When interposed at the interface of the heterojunction with As,
The area where the distortion introduced inside is outside the proper range
On the contrary, Ga is added to the heterojunction material._x In_1-x High in As
Electron mobility characteristics cannot be imparted. Therefore, such a
Select a method to introduce strain by changing the composition ratio.
In order to introduce distortion, it is provided on the buffer layer to introduce distortion.
This kind of Ga_x In_1-x The maximum thickness of As is 10 n
It is better to keep it at about m. Ga_x In_1-x Heterojunction with As layer
The material of the buffer layer is not limited to InP._y In_1-y
As may be used, such as GaInPAs lattice-matched to InP.
Any quaternary mixed crystal may be used. Al_y In_1-y As
Even when used as a buffer layer, Ga_x In_1-x
The method of providing strain inside both the As layer and the buffer layer is the root.
This is basically the same as the case of the InP buffer layer. As a buffer layer
InP or Al_y In_1-y Any semi conductor such as As
Even when the body material is used, the
Distance, Ga_x In_1-x Strain reaching inside the As layer
In the above, the area where the strain exists is within 10 nm, and the buffer layer
In the distortion existing inside the region, the region where the distortion exists is 30
There is no change in setting it to nm or less. Further, Ga_x In_1-x In As layer and buffer layer
Exist from the heterojunction interface to the inside of both layers
If the region of the strained layer that exceeds
Unnecessarily reduce the electron mobility of the material.
It is not preferable to introduce distortion. Also, Ga_x In_1-x
Maximum strain exists in either the As layer or the buffer layer
If the existing region exceeds the appropriate range, the two-dimensional electron itself becomes stationary
At high electron mobility.
Causes a situation that cannot be obtained stably. The present invention and conventional examples
Ga_0.47In_0.53Heating between As layer and InP buffer layer
Table 1 shows the difference in electron mobility at room temperature between the bonding materials.
Here, in the case of the heterojunction material according to the present invention,
The region where the maximum strain exists is Ga from the heterojunction interface._0.47
In_0.538 nm to the As layer side.
It in the layer was at 22 nm. On the other hand,
In this case, the region where the maximum strain exists in the InP layer
The same as in the case of_0.47In_0.53As layer
The position where the maximum strain exists in the heterojunction with the InP buffer layer
It was 12 nm from the combined interface. As shown in the table,
In the case according to the present invention with respect to the distortion existing in
There is a clear difference in room-temperature electron mobility, which is consistent with the present invention.
By providing distortion, the electron transfer is higher than in the past.
It can be seen that the mobility has been obtained. The application of these distortions
Adjusting the cooling rate after growth of the heterojunction material.
However, as mentioned above, the method of introducing distortion is
The method is not limited to this. [0030] [Table 1]Here, the electron transfer at room temperature described in the previous section.
In addition to explaining the cause of the difference,
Ga having a strain related to_0.47In_0.53As / InP
For heterojunction materials, a Shubni as shown in FIG.
Voltage due to the Shubnikov de Haas effect
Is observed, which proves the existence of two-dimensional electrons. one
On the other hand, according to the present invention, regarding the region of distortion as in the above-described conventional example.
For non-heterojunction materials, Shubnikov de Haar
Vibration is not recognized, and it is determined that two-dimensional electrons do not exist.
I will tell. Therefore, the electron mobility at room temperature described in the previous section
Is clearly due to the presence or absence of two-dimensional electrons.
Became. This means that the region in the layer where the strain exists
If it is not provided as shown, there is no two-dimensional electron
are doing. Here, Shuvnikov de Haas is once again
The vibration will be described. This is the effect of the electron in a strong magnetic field
Magnetic field of magnetoresistance (voltage) based on cyclotron motion
Refers to the change corresponding to the intensity, that is, the vibration (for example,
Toshiaki Ikoma, Hideaki Ikoma, "Introduction to Basic Properties of Compound Semiconductors"
Gate "(First edition issued September 10, 1991: Baifukan), 18
7-192 pages, or edited by The Physical Society of Japan
Physics and Applications ”(September 30, 1990, First Edition, Eighth Edition)
Row), pp. 42-46). This vibration is a two-dimensional electronic system
In the direction perpendicular to the plane where the two-dimensional electron exists
Appears remarkably when applied, and a magnetic field is applied horizontally.
Vibration does not normally occur. On the other hand, for three-dimensional electrons,
There is no magnetic field direction dependence such as resistance or voltage
(For example, Physics of Semiconductor Superlattice
"(September 30, 1990, first edition, 8th edition), p. 44
reference). Therefore, by observing this oscillation, the two-dimensional electron gas
This means that the presence or absence can be easily known. Specific measurement method
Ga_0.47In_0.53Taking As / InP heterojunction system as an example
First, a sample containing the same hetero-system
The sample is processed into a shape to be used for measurement, and the resistance, voltage, etc. of the sample are measured.
Electrodes for the resistance, and then the resistance
The field strength dependency and the magnetic field direction dependency may be measured. Hete
If there is a two-dimensional electron at the junction,
When a magnetic field is applied perpendicular to the heterojunction plane
The periodic change of the voltage value with the change of the magnetic field strength.
Motion, that is, Shubnikov de Haas oscillation is observed
It is. As described above, the substrate is formed on the InP single crystal substrate.
Buffer layer including elongated strain layer and Ga_xIn_1-x From the As layer
An epitaxial wafer with a heterojunction
A GaInAs Hall element is manufactured as a base material. Destination
Well-known photolithography technology and etching technology
Making full use of processing technology such as, it exhibits the function as a Hall element
Ga_x In_1-x In the As layer and InP buffer layer
Apply mesa etching to the element functional area.
Process into a shape. After mesa etching, input line
Then, an output electrode is formed. Next, here, Au · Ge is used as an electrode material.
Provides alloys, but is not otherwise limited to electrode materials
And the ohmic
It is only necessary to use a material that can provide a workable electrode. Next,
Insulating silicon dioxide (S
iO_Two ) The film is formed on the wafer surface by the
Is coated. Here, a silicon dioxide film is used as the coating film.
However, other insulating films such as silicon nitride (Si
N). Finally, known photolithography
A dicing line is formed by fee technology. Like this
The aim is to use a scriber for dicing (sucrib
er) and blades (brade) etc.
Mechanical damage to the taxi grown layer and hetero interface
This is to reduce in advance. After performing such processing, a GaInAs hole is formed.
The device is subjected to electrical characteristics evaluation, and a conventional heterojunction structure is used.
Properties of GaInAs Hall elements by neutron synthesis
I do. Here, the conventional GaInAs Hall element is
Extremely high cooling rate after epitaxial growth
Therefore, the region where the strained layer exists extends over the entire sensing layer.
Refers to an element composed of a terror junction material. The result of the comparison
FIG. 5 shows the distribution of the electron mobility in the state of the individually separated elements.
Shown as the difference. As is apparent from FIG.
In an aInAs Hall element, the average electron mobility is
A higher value is provided as compared with the conventional example. [0036] [Action] Ga_x In_1-x InP for As layer and buffer layer
Or Al_y In_1-yBoth layers of both layers such as As
Within a specific distance from the heterojunction interface composed of
The presence of a two-dimensional electric
Gas is present in the heterojunction material.
It has an effect of giving high electron mobility characteristics. [0037] EXAMPLES The present invention will be described in detail based on examples. FIG.
Is Ga according to the present invention._x In_1-x As (x represents the mixed crystal ratio
S) Schematic plane of Hall element with heterojunction with layer
FIG. FIG. 2 is a broken line in the schematic plan view shown in FIG.
It is the schematic of the perpendicular cross section along the direction of A-A '. Hete
In the formation of epitaxial wafers including B junctions
Has a specific resistance of about 10⁶ Ω · cm
(100) semi-insulating high-resistance InP single crystal substrate (10
1) Undoped InP serving as a buffer layer as a first layer
Layer (102) was grown to a thickness of about 100 nm. The
The carrier concentration of the InP layer (102) is adjusted to the hole (Hal).
l) As a result measured by the effect method, about 2 × 10^Fifteencm
^-3Met. Thereafter, on the above-mentioned InP buffer layer (102)
The carrier concentration is 2 × 10¹⁶cm^-3And the composition ratio is 0.47
Undoped n-type Ga_0.47In_0.53As (103)
Was deposited to a thickness of 250 nm. Here, as before
No spacer layer was inserted, and the InP buffer layer (10
2) and Ga_0.47In_0.53Hetero directly with As (103)
Joined. The interface of the heterojunction consisting of both layers
Shows the above-mentioned Shubnikov Haas oscillation, and 2
The existence of dimensional electrons has been proven. In this embodiment, Ga
_0.47In_0.53The valence of both As and InP crystal layers is
Monovalent cyclopentadienyl indium (chemical formula: C_Five
H_Five Temperature of 61 at normal pressure MOVPE using In) as the In source.
Grow at 0 ° C. The growth of the base material having the above structure has been completed.
Then, from the growth temperature of 610 ° C. to 200 ° C., 2
The material was cooled in 0 minutes. Therefore, the cooling rate is about
20 ° C. When this cooling rate is adopted, Ga_0.47
In_0.53Maximum strain exists in both As and InP layers
The existing region is Ga in the observation by the transmission electron microscope._0.47
In_0.538 nm from the heterojunction interface on the As layer side
20 nm on the InP layer side. Next, Ga_0.47In_0.53As layer (103)
Over the entire surface with a normal organic photoresist material.
After-known photolithography technology and etching technology
The area where input / output electrodes should be formed and the magnetic sensing part
The region (104) to be formed was processed into a mesa shape. This embodiment
Then, an inorganic acid was used for the mesa etching process. Thereafter, Ga_0.47In_0.53As layer (10
3) Cover the entire surface again with an organic resist material
Was. Next, each pair of the input electrode (105) and the output electrode
The resist existing in the region where the pole (106) is to be formed
Only material is removed using known photolithography technology
And Ga_0.47In_0.53Exposing the surface of the As layer (103)
I let you. After that, Au.G containing about 13% by weight of Ge
e alloy was vacuum deposited. Then, the wafer is
Immerse in the mixed solution, remove the resist material, and at the same time
A which is unnecessary in the production of the element deposited on the resist material
The u-Ge alloy film was removed by a so-called lift-off method. Next
At a temperature of 420
Heat treatment was carried out at ℃ for several minutes to obtain an ohmic electrode. Further, the input / output electrodes (105 and
106) and electrically connected to the pad electrode (107).
Each electrode was provided. The pad electrode (107) is as described above.
InP single crystal substrate (1
01) was placed on the surface layer. This is because Ga_0.47
In_0.53Directly at the heterojunction interface between the As layer and the InP buffer layer
Contact strain is introduced, and the two-dimensional electrons formed at the interface are adversely affected.
This is to prevent influence. Further, a table of the heterojunction material having undergone the above steps is shown.
The area other than the input / output electrodes on the surface is
And covered with a silicon dioxide film (108). Also, the oxide film
Was deposited at a thickness of about 400 nm. Further, the entire surface of the device is again converted to a general photo.
Holes formed over the entire surface of the wafer, covered with resist material
Die to separate the element into a single element and form a Hall element chip
Patterning to form the marking line (110)
Was. After that, the part corresponding to the dicing line (110)
The oxide film (108) existing immediately below
_0.47In_0.53As layer (103) and InP buffer layer (1
02) was sequentially removed by etching. More Etchin
To the surface of the InP single crystal substrate (101)
Remove the constituent materials until it becomes the dicing line (110).
did. Thereafter, the electrical characteristics of this Hall element,
The electron mobility, which affects the product sensitivity, is reduced by the conventional GaInA
It was compared with that of the s Hall element. The conventional ho
Element is Ga_0.47In_0.53As layer and InP buffer
The region of strain inherent in the layer is closer to the InP buffer layer than the hetero interface.
The maximum strain is located at about 38 nm on the side
Refers to That is, GaInA without two-dimensional electrons
s / InP refers to a heterojunction Hall element. As a result, the book
A new GaInAs device utilizing two-dimensional electrons according to the invention
The average room temperature electron mobility is 10,000 c.
m^Two / V · s, whereas in the prior art the average electron
Mobility is about 6,100cm^Two / V · s and about 40% difference
Appeared, and the GaInA according to the present invention was also considered in terms of electrical characteristics.
The superiority of the two-dimensional electron Hall element was shown. This is
Again, according to the present invention, stable generation of two-dimensional electrons
This is because it was possible. [0046] According to the present invention, the strained layer is provided within a specific distance from the hetero interface.
The GaInAs / InP heterojunction.
It has the effect of stably imparting electron mobility characteristics,
The stable supply of high-sensitivity GaInAs Hall elements
There are effects.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a two-dimensional electron GaInAs / In according to the present invention.
FIG. 3 is a schematic plan view of a P heterojunction Hall element. FIG. 2 is a diagram schematically showing a cross section along a broken line AA ′ of the Hall element shown in FIG. 1; FIG. 3 is a schematic diagram of a CAT analysis photograph of each semiconductor layer forming a hetero junction. FIG. 3A shows a case where no distortion exists, and FIG. 3B shows a case where distortion exists. FIG. 4 is a diagram showing Shubnikov de Haas oscillation under a strong magnetic field. However, the magnetic field is applied perpendicular to one main surface of the sample. FIG. 5 is a diagram showing a distribution of room-temperature electron mobility. [Description of Signs] (101) Fe-doped high-resistance InP single crystal substrate (102) InP buffer layer (103) Ga _0.47 In _0.53 As layer (104) Mesa region of element function part (105) Input electrode (106) Output electrode ( 107) Pad electrode (108) Silicon dioxide insulating film (109) Dicing line

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-198877 (JP, A) JP-A-4-298050 (JP, A) JP-A-61-20378 (JP, A) JP-A-Heisei 4- 162539 (JP, A) Proceedings of the 53rd Autumn Meeting of the Japan Society of Applied Physics, 1992, September 1992, No. 3, p. 1078 (16a-SZC-16) Denshi Research News, August 1992, Issue 511, pp. 6-10 (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01L 43/06 G01R 33/07

Claims (1)

(57) Claims 1. A gallium-indium arsenide (GaInAs) layer having a layer thickness of 50 nm or more and 500 nm or less, and a layer made of indium phosphide (InP) or aluminum indium arsenide (AlInAs). GaInAs using a two-dimensional electron gas generated by the heterojunction comprising a III-V compound semiconductor layer
In a two-dimensional electron Hall element, G
a GaInAs two-dimensional electron, wherein a strain exists at a distance of 10 nm or less from the inside of the aInAs layer and a strain exists at a distance of 30 nm or less from the heterojunction interface to the inside of the III-V compound semiconductor layer. Hall element.