JPS60201664A - Schottky junction type field-effect transistor and manufacture thereof - Google Patents

Abstract

PURPOSE:To contrive improvement both in function and high frequency characteristics of the titled field-effect transistor by a method wherein a gate electrode with which a Schottky junction is formed in the first semiconductor layer is provided in a buried form, the first electrode is formed on one surface of the first semiconductor layer, and then the second electrode is formed on the other surface of the first semiconductor layer. CONSTITUTION:A semiconductor layer L4 of n type, consisting of AlxGa1-xAs (0<x<1), for example, having a relatively low specific resistance such as 10<18> atom/cm<2> or above in the density of impurities and also having the bottom of a conduction band which is higher than the semiconductor layer L1 on the side of the semiconductor layer 1, is interposed between semiconductor layers L1 and L2. As a result, the travelling time required for the electron moving across the semiconductor layer l1 is markedly shorter when compared with the case of the conventional Schottky junction type field-effect transistor, and the field-effect transistor having remarkably excellent function and high frequency characteristics can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a semiconductor layer having a first conductivity type or a second IJ conductivity type opposite to the first conductivity type and having a relatively high specific resistance. In the semiconductor layer, a plurality of electrode elements are arranged at required intervals in the direction along the surface of the semiconductor layer, and a Schottky junction is formed between the electrode elements and the semiconductor layer. The present invention relates to a Schottky junction field effect transistor having a structure in which a gate electrode forming a Schottky junction with a semiconductor layer is buried, and to improvements in a manufacturing method thereof.

BACKGROUND OF THE INVENTION As a Schottky junction field effect transistor having the above-described structure, one having the structure described below with reference to FIG. 1 has been proposed.

That is, it has a semiconductor layer L1 made of, for example, GaAs, which has an n-type conductivity and has a relatively high specific resistance of 216 to 10 atOm/Cm3 when viewed from the traces of impurity 8I.

Therefore, the semiconductor layer L1 has a plurality of electrode cables Q arranged at required intervals in the direction along the surface thereof, and each of the electrode cables q and the semiconductor layer [1
For example, W, forming a Schottky junction J with
Metals such as Mo and Pt, or Ti-W compounds, T1.
A comb-shaped gate electrode G made of a metal compound such as W silicide is buried.

Further, on one surface (the upper surface in the figure) of the semiconductor layer L1, the same n-type as the semiconductor layer L1 is formed, but the impurity concentration is 1.
81101881011170m3 A semiconductor layer 12 made of GaAS, for example, having a relatively low resistivity of 81101881011170m3 or more is formed, while the semiconductor layer L2
An electrode E1 is ohmically attached thereto.

Further, on the other surface (lower surface in the figure) of the semiconductor ffL1, the semiconductor layer has the same n-type as 1, but has a relatively low specific resistance such as an impurity concentration rmiT of 1018 atoms/cm3 or more. , semiconductor layer L2
Similarly, a semiconductor layer L3 made of GaAs, for example, is formed, and an electrode E2 is ohmically attached to the surface of the semiconductor layer 30 opposite to the semiconductor layer L1 side.

The above is the configuration of the conventionally proposed Schottky junction field effect transistor.

Note that the Schottky junction field effect transistor having such a configuration is actually manufactured by the following method.

That is, although detailed illustrations and detailed explanations are omitted, a semiconductor layer L5 (not shown), which is a half of the semiconductor layer L1 on the semiconductor layer L3 side, is formed on the semiconductor substrate as the semiconductor layer L3, and Next, the above-mentioned gate electrode G is formed on the semiconductor layer L5 so as to form a Schottky junction j1 that constitutes the above-mentioned Schottky junction J with the semiconductor layer L5, and then the semiconductor layer 5 On top, a semiconductor layer L1
The semiconductor layer [6
(not shown) is buried in the gate electrode G and forms a Schottky junction j2 forming a Schottky junction J between the gate electrode G and the semiconductor layer L1 described above.
The above-mentioned semiconductor layer L2 is formed on the semiconductor layer L1, and then an electrode E1 is formed on the semiconductor layer L2 and on the surface of the semiconductor layer L3 opposite to the semiconductor layer L1 side.
, and E2, the conventional Schottky junction field effect transistor described above in FIG. 1 is manufactured.

According to the configuration of the conventional Schottky junction field effect transistor described above in FIG. is a semiconductor layer serving as an electrode, the semiconductor layer L1 is an active layer, the semiconductor layer L2 is a semiconductor layer serving as an electrode, and the electrode E1 acts as a source electrode, forming a region between adjacent electrode elements 0 of the gate electrode G of the semiconductor layer L1. , a current flows from the electrode E2 side toward the electrode E1 side through the semiconductor layer 3, the region between adjacent electrode elements 9 of the gate electrode G of the semiconductor layer L1, and the semiconductor layer L2 in these order.

In addition, if a DC power source with the electrode E1 side positive is connected between the electrodes E1 and E2, the electrode E1 is the drain electrode, the semiconductor layer L3 is a semiconductor layer that also serves as an electrode, the semiconductor layer L1 is an active layer, and the semiconductor layer L2 is an electrode. The combined semiconductor layer, the electrode E2, acts as a source electrode, and the semiconductor layer L2 is applied from the electrode E1 side to the region between the adjacent electrode elements 9 of the gate electrode G of the semiconductor layer L1.
, the region between adjacent electrode elements 0 of the gate electrode G of the semiconductor layer L1, and the semiconductor layer L3 in order, and a current flows toward the electrode E2 side.

Furthermore, if a control voltage is applied between the electrode E1 or E2 and the gate electrode G, the control voltage is applied to the semiconductor layer L via the semiconductor layers L2 and Ll or the semiconductor layers L3 and Ll.
Since the voltage is applied across the Schottky junction J formed between the gate electrode G and the electrode element q of the semiconductor layer L1, the semiconductor The depletion layer expanding from the Schottky junction J formed between the layer L1 and the adjacent electrode element q of the gate electrode G expands depending on the polarity and value of the control voltage (the phase of the gate electrode G of the semiconductor layer L1). (including the case where it spreads over the entire area between adjacent electrode elements 9).

Therefore, according to the conventional Schottky junction field effect transistor shown in FIG. 1, a load is connected between electrodes E1 and E2 via a DC power supply, and
By applying a control voltage between the control voltage and the gate electrode G, a current controlled according to the polarity and value of the control voltage (including when the value is zero) can be supplied to the load. Function as a transistor can be obtained.

However, the conventional Schottky junction field effect transistor shown in FIG. 1 has a certain limit in its ability to function as a field effect transistor with good high frequency characteristics.

The reason is as follows.

That is, in the case of the conventional Schottky junction field effect transistor shown in FIG. 1, its high frequency characteristic figure of merit (flIlax) is proportional to its cutoff frequency f semiconductor layer L
When the time taken for electrons to travel across the semiconductor layer L1 when a current flows through the semiconductor layer L1 is τ, it is expressed as fT=1/2πτ. Therefore, the shorter the time for electrons traveling across the semiconductor layer L1 to travel across the semiconductor layer L1, the better the high frequency characteristics are.

However, in the case of the conventional Schottky junction field effect transistor shown in FIG.
If the N current flowing through the electrode E1 is a current flowing from the electrode E2 side to the electrode E1 side, the electrons traveling across the semiconductor layer L1 from the semiconductor layer L2 side to the semiconductor layer L3 side will flow through the electrodes E1 and E1.
The semiconductor H[2 is accelerated from the side toward the semiconductor layer L3 side by the electric field generated in the semiconductor layer L1 due to the voltage of the DC power supply applied between the semiconductor layer L1. Since only the semiconductor layer L2 having a low specific resistance is connected to the electrode E2 side, the semiconductor layer L1
The electrons traveling across the semiconductor layer L1 are only accelerated from a state where their initial velocity is zero. Therefore, in this case, when the electrons traveling across the semiconductor layer L1 travel across the semiconductor layer L1, This is because it took a relatively long time.

Further, as described above, when the current flowing through the semiconductor layer L1 is a current flowing from the electrode E1 side to the electrode E2 side, the electrons traveling across the semiconductor layer L1 from the semiconductor layer L3 side to the semiconductor layer L2 side are Due to the electric field generated in the semiconductor layer L1 by the voltage of the DC power supply applied between E1 and E2, the acceleration is accelerated from the semiconductor layer L3 side toward the semiconductor layer [2 side. Electrode E1
Since the semiconductor layer L2 having a low resistivity is only connected to the side, the electrons traveling across the semiconductor 1iEtL1 are only accelerated from the initial velocity of zero, as described above. Therefore, in this case as well, it takes a relatively long time for the electrons traveling across the semiconductor layer L1 to travel across the semiconductor layer L1.

According to the object of the present invention, the present invention has a function as a field effect transistor having significantly better high frequency characteristics than the conventional Schottky junction field effect transistor described above in FIG. This paper aims to propose a novel Schottky junction field effect transistor and its manufacturing method.

DISCLOSURE OF THE INVENTION According to the Schottky junction field effect transistor according to the present invention, as in the case of the conventional Schottky junction field effect transistor described above in FIG. A first semiconductor layer having an opposite second conductivity type and a relatively high specific resistance, and arranged within the Ml semiconductor layer at a required interval in a direction along the surface direction of the Ml semiconductor layer. A gate electrode having a plurality of electrode elements forming a Schottky junction with the first semiconductor layer is embedded;
A first electrode is formed with or without a second semiconductor layer having the same conductivity type as the first semiconductor layer and a relatively low resistivity; A configuration in which a second electrode is formed on the other surface with or without a third semiconductor layer having the same conductivity type as the first semiconductor layer and having a relatively low specific resistance. has.

However, in the Schottky junction field effect transistor according to the present invention, there is a gap between the first semiconductor layer and the second semiconductor layer or the first electrode, or between the first semiconductor layer and the third semiconductor layer or the second electrode. has the same conductivity type as the first semiconductor layer and a relatively low resistivity, and the first semiconductor layer has the first conductivity type or the second conductivity type. Depending on whether the first semiconductor layer side has a higher conduction band bottom than the first semiconductor layer or a lower valence band top than the first semiconductor layer side. A fourth semiconductor layer is inserted therein.

According to the Schottky junction field effect transistor according to the present invention, as in the case of the conventional Schottky junction field effect transistor described above in FIG. If a load is connected and a control voltage is applied between the first or second electrode and the gate electrode, a controlled current (even if the value is zero) is generated according to the polarity and value of the control voltage. ) can be supplied to the load as a field effect transistor.

Also, as in the case of the conventional Schottky junction field effect transistor described above in FIG. 1, when a current flows across the first semiconductor layer, electrons traveling across the first semiconductor layer As in the case of the conventional Schottky junction field effect transistor described above in FIG. , is accelerated.

However, in the case of the Schottky junction field effect transistor according to the present invention, between the first semiconductor layer and the second semiconductor layer or the first electrode, or between the first semiconductor layer and the third
or the second electrode, the first semiconductor layer has the same conductivity type as the first semiconductor layer and has a relatively low specific resistance, and the first semiconductor layer has the first conductivity type. Depending on whether the first semiconductor layer side has a higher conduction band bottom than that of the first semiconductor layer or has a higher conduction band bottom than that of the first semiconductor layer, Since the fourth semiconductor layer having a low valence band peak is inserted, electrons or holes from the fourth semiconductor layer are transferred to the first semiconductor layer side of the fourth semiconductor layer. The electron beam enters the first semiconductor layer with energy depending on the difference between the bottom of the conduction band or the top of the valence band between the electron beam and the first semiconductor layer, and is accelerated within the first semiconductor layer.

Therefore, the time taken for electrons or holes to travel across the first semiconductor layer is
Since it is much shorter than the conventional Schottky junction field effect transistor described above in FIG. 1, the function as a field effect transistor is It has the characteristic that it can be obtained as having significantly better high frequency characteristics compared to the conventional method.

Further, according to the first manufacturing method of the Schottky junction field effect transistor according to the present invention, the Schottky junction field effect transistor has a first conductivity type or a second conductivity type opposite to the first conductivity type, and has a relatively high specific resistance. A first Schottky junction is formed between the fifth semiconductor layer and the fifth semiconductor layer, and a plurality of electrode elements arranged at required intervals in the direction along the surface of the fifth semiconductor layer. A process of forming a gate electrode having the same conductivity type as the fifth semiconductor layer and a relatively high specific resistance, and embedding the gate electrode to form a bond with the gate electrode. forming a sixth semiconductor layer forming a second Schottky junction therebetween, embedding the gate electrode, and forming a Schottky junction consisting of the first and second Schottky junctions between the gate electrode; a step of forming a first semiconductor layer consisting of a fifth and a sixth semiconductor layer having the same conductivity type and a relatively low resistivity on the first semiconductor layer; Depending on whether the semiconductor layer has the first conductivity type or the second conductivity type, the first semiconductor layer side has a conduction band bottom higher than that of the first semiconductor layer. and forming a fourth semiconductor layer having a lower valence band peak than the first semiconductor layer.

Further, according to the second manufacturing method of the Schottky junction field effect transistor according to the present invention, the Schottky junction field effect transistor has a first conductivity type or a second conductivity type opposite to the first conductivity type, and has a relatively low specific resistance. forming a fourth semiconductor layer having the same conductivity type and relatively low resistivity on the third semiconductor layer having the same conductivity type; In addition, the third semiconductor of the fourth semiconductor layer has a relatively high specific resistance, and depending on whether the fourth semiconductor layer has the first conductivity type or the second conductivity type. The layer side has a lower conduction band bottom than the side opposite to the third semiconductor layer side, or the third semiconductor layer side of the fourth semiconductor layer has a higher valence band top than the side opposite to the third semiconductor layer side. a step of forming a fifth semiconductor layer; a step of forming a fifth semiconductor layer; a step of forming a gate electrode forming a first Schottky junction therebetween; and burying the gate electrode on a fifth semiconductor layer having the same conductivity type and relatively high resistivity. a sixth semiconductor layer forming a second Schottky junction with the gate electrode, burying the gate electrode and forming a first and second Schottky junction between the gate electrode; and forming a first semiconductor layer including fifth and sixth semiconductor layers forming a Schottky junction.

According to the first and second manufacturing methods of the Schottky junction field effect transistor according to the present invention, the Schottky junction field effect transistor according to the present invention having the characteristics described above can be easily manufactured. .

First, a preferred embodiment of the Schottky junction field effect transistor according to the present invention will be described.

Example 1-1 FIG. 2 shows a first example of a Schottky junction field effect transistor according to the present invention.

In FIG. 2, parts corresponding to those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

A first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. 2 has the structure of the conventional Schottky junction field effect transistor described above in FIG. It has a relatively low specific resistance of 8 to 10 atoms/cm3 or more in terms of impurity concentration, and as shown in FIG. For example, A IX Ga1-x with a band bottom
It has the same structure as the conventional Schottky junction field effect transistor described above in FIG. 1, except that a semiconductor layer L4 made of As (0<, x≦1) is interposed.

In this case, the difference ΔEC seen at the bottom of the conduction band between the semiconductor layer L1 side of the semiconductor layer L4 and the semiconductor layer L4 side of the semiconductor layer L1 is A 1xGa1-x as shown in FIG.
It takes a value depending on the value of X of As.

The above is the configuration of the first embodiment of the Schottky junction field effect transistor according to the present invention.

According to this configuration, except for the matters mentioned above, it has the same configuration as the conventional Schottky junction field effect transistor described above in FIG. As in the case of the conventional Schottky junction field effect transistor described above, a load is connected between the electrodes E1 and 12 via a DC power supply, and a control voltage is applied between the electrode E1 or E2 and the gate electrode G. By applying , it is possible to supply a current controlled according to the polarity and value of the control voltage to the load.

Further, according to the Schottky junction field effect transistor according to the present invention shown in FIG. 2, as in the case of the conventional Schottky junction field effect transistor described above in FIG.
When a current flows across the semiconductor layer L1, electrons traveling across the semiconductor layer L1 are transferred to the electrodes E1 and 12.
Acceleration is caused by an electric field generated within the semiconductor layer L1 by the voltage of the DC power supply applied between them.

However, in the case of the Schottky junction field effect transistor according to the present invention shown in FIG. 2, between the semiconductor layer L1 and the semiconductor layer L2, the conduction band bottom on the semiconductor layer L1 side is higher than that of the semiconductor layer L1. Therefore, electrons are transferred from the semiconductor layer L4 to an energy level corresponding to the difference in the bottom of the conduction band between the semiconductor layer L1 side of the semiconductor layer [4] and the semiconductor layer L1. With this, it enters the semiconductor layer L1 and is accelerated within the semiconductor layer L1.

Therefore, the electrons traveling across the semiconductor JBL1 are
Since it has a much shorter time than the conventional Schottky junction field effect transistor described above in FIG.
It is characterized in that it can function as a field effect transistor with much better high frequency characteristics than the conventional Schottky junction field effect transistor described above in FIG.

Example 1-2 Next, a second example of the Schottky junction field effect transistor according to the present invention will be described.

The second embodiment of the Schottky junction field effect transistor according to the present invention has the structure of the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. Semiconductor layer [1,
L2, L3 and L4 are p-type instead of n-type,
Accordingly, as shown in FIG. 3, the semiconductor layer [4 has a lower valence band peak on the semiconductor layer L1 side than on the semiconductor layer L1 side (the difference between them is ΔF). The configuration is similar to that of the first embodiment according to the invention shown in FIG. 2, except as shown in FIG.

The above is the configuration of the second embodiment of the Schottky junction field effect transistor according to the present invention.

According to the Schottky junction field effect transistor having such a configuration, it is the same as the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. 2, except for the matters mentioned above. Although a detailed explanation will be omitted, in the description of the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. ``The bottom of the conduction band is higher than that of the semiconductor layer Ll'' and ``has a lower valence band than the semiconductor layer L1'', and further , an operation in which "electrons" are replaced with "holes" is obtained, and the same excellent effects as in the case of the first embodiment can be obtained.

Next, a third embodiment of the Schottky junction field effect transistor according to the present invention will be described.

The second embodiment of the Schottky junction field effect transistor according to the present invention has the structure of the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. The structure is similar to that of the first embodiment of the present invention shown in FIG. 2, except that the semiconductor layer L2 is omitted.

The above is the configuration of the second embodiment of the Schottky junction field effect transistor according to the present invention.

According to the Schottky junction field effect transistor having such a configuration, it is the same as the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. 2, except for the matters mentioned above. Although a detailed explanation will be omitted, it is characterized in that the same effects as in the first embodiment of the Schottky junction field effect transformer and transistor according to the present invention shown in FIG. 2 can be obtained. .

Example 1-4 Next, a second example of the Schottky junction field effect transistor according to the present invention will be described.

The second embodiment of the Schottky junction field effect transistor according to the present invention has the structure of the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. Instead of the semiconductor layer [4 being interposed between the semiconductor layers L1 and L2,
The structure is similar to that of the first embodiment according to the present invention shown in FIG. 2, except that it is interposed between the semiconductor layers L1 and 13.

The above is the configuration of the second embodiment of the Schottky junction field effect transistor according to the present invention.

According to the Schottky junction field effect transistor having such a configuration, it is the same as the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. 2, except for the matters mentioned above. Although a detailed explanation will be omitted, this embodiment has the feature that the same operation and effect as the first embodiment of the Schottky junction field effect transistor can be obtained.

In the description of the first embodiment of the Schottky junction field effect transistor, the "bottom of the arm" is referred to as the "bottom of the valence band".
In addition, "Has a higher conduction band bottom than the semiconductor layer Ll" is read as "Has a lower valence band than the semiconductor layer L1", and further, "The bottom of the conduction band is higher than the semiconductor layer L1" and It has the characteristic that the effect obtained by replacing J with "hole" can be obtained.

Example 1-2 Next, a second example of the Schottky junction field effect transistor according to the present invention will be described.

The second embodiment of the Schottky junction field effect transistor according to the present invention has the structure of the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. semiconductor layer Ll,
N2, L3 and L4 are p-type instead of n-type,
Accordingly, as shown in FIG. 3, the semiconductor layer L4 has a lower valence band peak on the semiconductor layer L1 side than on the semiconductor layer L1 side, as shown in FIG. The configuration is similar to that of the first embodiment according to the present invention shown in FIG.

The above is the configuration of the second embodiment of the Schottky junction field effect transistor according to the present invention.

According to the Schottky junction field effect transistor having such a configuration, it is the same as the first embodiment of the Schottky junction field effect transistor according to the present invention shown in Section 2-, except for the matters mentioned above. Although a detailed explanation will be omitted, in the explanation of the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. bottom"
In addition, "has a higher conduction band bottom than the semiconductor layer Ll" has been replaced with "has a lower valence band than the semiconductor layer L1", and further, "has a lower conduction band bottom than the semiconductor layer L1", It is characterized by the effect that can be obtained by reading ``hole'' instead of ``hole''.

Next, a preferred embodiment of the method for manufacturing a Schottky junction field effect transistor according to the present invention will be described.

Example 2-1 FIG. 6 shows a first example of the method for manufacturing a Schottky junction field effect transistor according to the present invention, which manufactures the first example of the Schottky junction field effect transistor according to the present invention shown in FIG. shows.

In FIG. 6, parts corresponding to those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

A first embodiment of the method for manufacturing a Schottky junction field effect transistor according to the present invention, shown in FIG. 6, involves the following sequential steps.

That is, a semiconductor cloud plate (hereinafter referred to as semiconductor layer L3 for simplicity) made of GaAs is prepared as the semiconductor layer L3 (FIG. 6A).

Then, on the semiconductor layer L3, a semiconductor layer L5, which is the half of the semiconductor layer L1 on the semiconductor layer L3 side, is formed of GaAS by a known vapor phase growth method (FIG. 6). B) Next, a gate electrode G is formed on the semiconductor mL5 by a method known per se (sixth step).
Figure C).

Next, the first semiconductor layer L3 is placed on the semiconductor layer L5.
The semiconductor layer [5, which is the half on the opposite side, is formed of GaAS by vapor phase growth (FIG. 6D). In this case, the vapor phase growth method uses trimethyl gallium gas or triethyl gallium gas as a raw material gas,
A mixed gas of arsine (AsH3) gas as a raw material gas and hydrogen as a carrier gas, with a flow m of hydrogen as a carrier gas of 41/min, and trimethyl gallium gas or triethyl gallium gas and alumin gas as raw material gases. , respectively 3X10 for the mixed gas
It is possible to use a vapor phase growth method with a mole fraction of 3×10 −5 and a temperature of 600 to 700° C.

Next, a semiconductor layer 4 is formed on the semiconductor layer L1 by vapor phase epitaxy using A I Ga 1-x As (O<x
<1) (Fig. 6E). In this case, the vapor phase growth method uses melimethyl gallium gas or triethyl gallium gas as a raw material gas, trimethylaluminum gas or triethylaluminum gas as a raw material gas, arsine gas as a raw material gas, and n
A mixed gas of hydrogen selenide gas as a type impurity gas and hydrogen as a carrier gas is used with a flow rate of hydrogen as a carrier gas of 41/min, and trimethyl gallium gas, trimethyl gallium gas, trimethyl aluminum gas as a raw material gas. Or, triethylaluminum gas and arsine gas are mixed at a mole fraction of 3 x 10, 2 x 10-5, and 3 x 10 to 3 x 10' mole fraction, respectively, with respect to the mixed gas; Hydrogen selenide gas as an n-type impurity gas is
It is possible to use a vapor phase growth method with a mole fraction of 7 and a temperature of 600 to 700°C.

Next, a semiconductor layer L2 made of GaAS is formed on the semiconductor layer L4 by a vapor phase growth method (FIG. 6F). The vapor phase growth method in this case may be the same vapor phase growth method as that used for forming the semiconductor layer L5.

Next, electrodes F1 and E are formed on the surface of the semiconductor layer L2 opposite to the semiconductor layer L4 side and on the surface of the semiconductor layer L3 opposite to the semiconductor layer L1 side by a method known per se.
form 2.

In this way, the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. 2 is obtained.

The above is the first embodiment of the method for manufacturing a Schottky junction field effect transistor according to the present invention.

According to the first step in the method for manufacturing a Schottky junction field effect transistor according to the present invention, as is clear from the above, the second step can be carried out in an extremely simple process.
The characteristic Schottky junction field effect transistor according to the invention as shown in the figure can be easily manufactured.

Further, in this case, if the semiconductor layers L6, L4, and L2 are formed by the vapor phase growth method using organic gallium gas, organic aluminum gas, and organic gallium gas, as described above, the semiconductor layer L6 can be formed. After that, the semiconductor layer L4 can be formed simply by adding organic aluminum gas to the organic gallium gas at that time, and the semiconductor layer L4 can be formed simply by forming the semiconductor layer L4 and then stopping using the organic aluminum gas. Since L2 can be formed, the Schottky junction field effect transistor according to the present invention shown in FIG. 2 can be manufactured more easily.

Embodiment 2-2 In FIG. 6, parts corresponding to those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

A first embodiment of the method for manufacturing a Schottky junction field effect transistor according to the present invention, shown in FIG. 6, involves the following sequential steps.

That is, a semiconductor substrate made of GaAs (hereinafter referred to as semiconductor layer L3 for simplicity) as the semiconductor layer L3 is prepared (FIG. 6A).

Next, a gate electrode G is formed on the semiconductor layer L5 by a method known per se (FIG. 6C).

Next, the semiconductor layer L3 of the semiconductor layer L1 is placed on the semiconductor layer L5.
The semiconductor layer L5, which is the half on the opposite side, is formed of GaAs by vapor phase growth (FIG. 6D). In this case, the vapor phase growth method uses trimethyl gallium gas or triethyl gallium gas as a raw material gas,
A mixed gas of arsine (AsH3) gas as a raw material gas and hydrogen as a carrier gas, with a flow rate of hydrogen as a carrier gas of 41/min, and trimethyl gallium gas or triethyl gallium gas and alumin gas as raw material gases. , respectively 3X10 for the mixed gas
-4 mole fraction and 3×10 −5 mole fraction, and a vapor phase growth method with a temperature of 600 to 700° C. is possible.

Next, on the semiconductor layer L1, a semiconductor layer L4 is formed by A I Ga1. It is formed of As (O<x<1) (Fig. 6E). In this case, the vapor phase growth method uses melimethylgallium gas or triethylgallium gas as a raw material gas, trimethylaluminum gas or triethylaluminum gas as a raw material gas, arsine gas as a raw material gas, and selenium as an n-type impurity gas. A mixed gas of hydrogen chloride gas and hydrogen as a carrier gas, with a flow rate of hydrogen as a carrier gas of 41/min, trimethyl gallium gas or trimedel gallium gas, triethyl aluminum gas or triethyl aluminum gas as a raw material gas, and arsine gas to the mixed gas at a mole fraction of 3×10, 2×10−5, and 3×10−4 to 3×10−5, respectively, and n
It is possible to use a vapor phase growth method in which hydrogen selenide gas as a type impurity gas is used at a mole fraction of 10<-7> and the temperature is set at 600 to 700[deg.]C.

Then, on the semiconductor layer L3, a semiconductor layer L5, which is the half of the semiconductor layer [1 on the semiconductor layer L3 side], is formed of GaAS by a vapor phase growth method that is known per se. Figure B) In the above description, only one embodiment of the Schottky junction field effect transistor according to the present invention has been shown, and two embodiments have been shown regarding the manufacturing method of the Schottky junction field effect transistor according to the present invention. Just stopped.

For example, the semiconductor layers L1, L2, and L3 are made of InGaAS or InGaAsP, and the semiconductor layer L4 is made of InP. Various modifications and changes may be made without departing from the spirit of the invention.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a conventional square junction field effect transistor. FIG. 2 is a cross-sectional view showing a first embodiment of a Schottky junction field effect transistor according to the present invention. FIG. 3 is a diagram showing the relationship between the semiconductor layer 11 and L4, which are the main parts thereof, in terms of energy bands. In FIG. 4, the main part of the semiconductor layer L4 is AlxGa1-X
FIG. 7 is a diagram showing the relationship between the difference in the bottom of the conduction band between the semiconductor layers L4 and L1 with respect to X when the semiconductor layer is made of AS. FIG. 5 is a cross-sectional view showing a second embodiment of the Schottky junction field effect transistor according to the present invention. FIG. 6 shows a sequential sequence of steps illustrating a first embodiment of a method for manufacturing a Schottky junction field effect transistor according to the present invention to produce a first embodiment of a Schottky junction field effect transistor according to the present invention shown in FIG. It is a line sectional view in a process. FIG. 7 shows a sequential sequence of steps illustrating a second embodiment of a method for manufacturing a Schottky junction field effect transistor according to the present invention to produce a second embodiment of a Schottky junction field effect transistor according to the present invention shown in FIG. It is a line sectional view in a process. L1 to L4...Semiconductor layer L5. L6...Semiconductor layer G constituting semiconductor BL1...Gate electrode Q
・・・・・・・・・・・・・・・ Electrode element J of gate electrode G, j1. j2 ・・・・・・・・・・・・・・・Schottky junction E1; E2・・・Electrode applicant Nippon Telegraph and Telephone Public Corporation agent Patent attorney Masaharu Tanaka No. 3 No. 1111 ◆ Uchisaiwaicho 1-1-6 Name
(422) Nippon Telegraph and Telephone Public Corporation Representative Tsune Shinfuji 4, Agent address 5-7 Kojimachi, Chiyoda-ku, Tokyo 102
Hidekazu Kioicho TBR No. 820 No. 5, Date of amendment order Voluntary amendment 6, Number of inventions increased by amendment None 7, Subject of amendment Full details of the specification (corrected full text), Title of invention Schottky junction field effect transistor and The manufacturing method thereof, Claim 1, comprising a first semiconductor layer having a first conductivity type or a second conductivity type opposite to the first conductivity type and having a relatively high specific resistance; A gate having a plurality of electrode elements arranged at required intervals in a direction along the surface of the first semiconductor layer, and forming a Schottky junction with the first semiconductor layer. An electrode is buried on one surface of the first semiconductor layer, with or through a second semiconductor layer having the same conductivity type as the first semiconductor layer and having a relatively low specific resistance. a third semiconductor layer having the same conductivity type as the first semiconductor layer and a relatively low resistivity on the other surface of the first semiconductor layer; In a Schottky junction field effect transistor in which a second electrode is formed with or without intervening, between the first semiconductor layer and the second semiconductor layer or the first electrode, or between the first semiconductor layer and the second semiconductor layer or the first electrode; 1 semiconductor layer and the third semiconductor layer
or the second electrode, the first semiconductor layer has the same conductivity type as the first semiconductor layer and has a relatively low resistivity, and the first semiconductor layer has the first conductivity type. The first semiconductor layer side has a conduction band bottom higher than that of the first semiconductor layer, or has a conduction band bottom higher than that of the first semiconductor layer, or A Schottky junction field effect transistor characterized in that a fourth semiconductor layer having a valence band peak lower than that of the semiconductor layer is interposed. 2. On the fifth semiconductor layer having the first conductivity type or a second conductivity type opposite to the first conductivity type and having a relatively high specific resistance, a required interval is formed in the direction along the surface of the fifth semiconductor layer. a step of forming a gate electrode having a plurality of electrode elements arranged so as to maintain the same and forming a first horizontal junction with the fifth semiconductor layer; A second Schottky junction is formed on the semiconductor layer, having the same conductivity type and relatively high resistivity, and embedding the gate electrode to form a second Schottky junction with the gate electrode. 6 is formed to bury the gate electrode and to form the first semiconductor layer between the gate electrode and the first semiconductor layer.
and a second Schottky junction, forming a first semiconductor layer composed of the fifth and sixth semiconductor layers forming a Schottky junction, and forming a first semiconductor layer of the same conductivity type as the fifth and sixth semiconductor layers on the first semiconductor layer. and has a relatively low specific resistance, depending on whether the first semiconductor layer has a first conductivity type or a second conductivity type. forming a fourth semiconductor layer having a conduction band bottom higher than that of the first semiconductor layer or having a valence band top lower than that of the first semiconductor layer; A method for manufacturing a Schottky junction field effect transistor, comprising the steps of: 3. In the method for manufacturing a Schottky junction field effect transistor according to claim 2, in the step of forming the M6 semiconductor layer, the sixth semiconductor layer is formed into a semiconductor layer made of GaAS by vapor phase growth. and forming the fourth semiconductor layer, the step of forming the fourth semiconductor layer.
A semiconductor layer of AlxGa1-xAs (0<x<1) is grown by vapor phase growth using organic aluminum gas.
A method for manufacturing a Schottky junction field effect transistor, characterized in that it is formed in a semiconductor layer consisting of: 4. A method for manufacturing a Schottky junction field effect transistor according to claim 3, characterized in that trimethylaluminum gas or triethylaluminum gas is used as the organic aluminum gas. 5. On a third semiconductor layer having a first conductivity type or a second conductivity type opposite to the first conductivity type and having a relatively low specific resistance, a layer having the same conductivity type as the first conductivity type and a comparatively low resistivity. forming a fourth semiconductor layer having a relatively low specific resistance, and having the same conductivity type as the fourth semiconductor layer and a relatively high specific resistance; The bottom of the conduction band is lower than that on the side of the fourth semiconductor layer opposite to the third semiconductor layer, depending on whether the fourth semiconductor layer has the first conductivity type or the second conductivity type. or having a higher valence band peak than the side of the fourth semiconductor layer opposite to the third semiconductor layer; A first Schottky junction is formed between the fifth semiconductor layer and the fifth semiconductor layer, having a plurality of electrode elements arranged at required intervals in the direction along the surface of the fifth semiconductor layer. a step of forming a gate electrode having the same conductivity type as the fifth semiconductor layer and a relatively high specific resistance, and burying the gate electrode between the fifth semiconductor layer and the fifth semiconductor layer; forming a sixth semiconductor layer forming a second Schottky junction, burying the gate electrode and forming a Schottky junction consisting of the first and second Schottky junctions between the sixth semiconductor layer and the gate electrode; forming a first semiconductor layer made up of the fifth and sixth semiconductor layers. 6. In the method for manufacturing a Schottky junction field effect transistor according to claim 5, in the step of forming the fourth semiconductor layer, the fourth semiconductor layer is formed by vapor phase growth using organic aluminum gas. By law, Alx
In the step of forming the fifth semiconductor layer, the fifth semiconductor layer is formed of Ga1-x As (0<X<1).
In the step of forming a semiconductor layer made of GaAS by a vapor phase epitaxy method and forming the sixth semiconductor layer, the sixth semiconductor layer is formed by a GaAS semiconductor layer by a vapor phase epitaxy method.
A method for manufacturing a Schottky junction field effect transistor, characterized in that it is formed in a semiconductor layer made of aAS. 7. A method for manufacturing a Schottky junction field effect transistor according to claim 6, characterized in that trimethylaluminum gas is used as the organic aluminum gas. 3. Detailed Description of the Invention Field of the Invention The present invention relates to a semiconductor layer having a first conductivity type or a second conductivity type opposite to the first conductivity type and having a relatively high specific resistance. In the semiconductor layer, a plurality of electrode elements are arranged at required intervals in the direction along the surface of the semiconductor layer, and a Schottky junction is formed between the electrode elements and the semiconductor layer. The present invention relates to a Schottky junction field effect transistor having a structure in which a gate electrode forming a Schottky junction with a semiconductor layer is buried, and to improvements in a manufacturing method thereof. 11th Group Oninao I As a Schottky junction field effect transistor having the above-described structure, one having the structure described below with reference to FIG. 1 has been proposed. That is, it has n-type and has an impurity S degree of 1012~
11016atO/Cm3 has a semiconductor layer L1 made of, for example, GaAS and has a relatively high resistivity. Therefore, the semiconductor layer 1 has a plurality of electrode elements q arranged at required intervals in the direction along the surface thereof, and there is a connection between each of the electrode elements q and the semiconductor layer L.
For example, W forming a Schottky junction J with 1.
, MO, metals such as Pt, or Ti-W compounds, Ti
- A comb-shaped gate electrode G made of a metal compound such as W silicide is buried. In addition, although it has the same n-type as the semiconductor layer L1 on one side (the upper surface in the figure) of the semiconductor layer L1, it has a relatively low specific resistance such that the impurity concentration is higher than T1018 atoms/co+3. A semiconductor layer L2 made of, for example, GaAs is formed, and on the other hand, the semiconductor layer L2
An electrode E1 is ohmically attached thereto. Furthermore, the other surface (lower surface in the figure) of the semiconductor layer L1
The upper layer has the same n-type as the semiconductor layer L1, but the impurity concentration is 10atOIIl/Cl11.
A semiconductor layer L3 made of GaAs, for example, is formed similarly to the semiconductor layer L2, and has a relatively low resistivity of 3 mm or more. An electrode E2 is ohmically attached to the surface. The above is the configuration of the conventionally proposed Schottky junction field effect transistor. Note that the Schottky junction field effect transistor having such a configuration is actually manufactured by the following method. That is, although detailed illustrations and detailed explanations are omitted, the above-mentioned semiconductor layer L1 is placed on the semiconductor substrate as the above-mentioned semiconductor layer L3.
A semiconductor layer L5 (not shown) is formed on the semiconductor layer L5 (not shown), and then the above-mentioned gate electrode G is formed on the semiconductor layer L5, and the above-mentioned Schottky layer is formed between the semiconductor layer L5 and the semiconductor layer L5 (not shown). A semiconductor layer 16 (not shown) is formed to form a Schottky junction j1 constituting the junction J, and then a semiconductor layer 16 (not shown) is formed on the semiconductor layer L5 to form a half of the semiconductor layer L1 on the side opposite to the semiconductor layer L3 side. is a Schottky junction j2 that buries the gate electrode G and forms a Schottky junction J between it and the gate electrode G.
The above-described semiconductor layer L1 is formed by forming the semiconductor layer L1, and then the above-described semiconductor layer L2 is formed on the semiconductor layer L1.
Then, on the semiconductor layer L2 and 13% of the semiconductor layer
An electrode E is provided on the surface opposite to the semiconductor layer L1 side.
1 and E2, the conventional Schottky junction field effect transistor described above in FIG. 1 is manufactured. According to the configuration of the conventional Schottky junction field effect transistor described above in FIG.
If you connect a DC power source with the electrode E2 side positive, the electrode E2
acts as a train electrode, the semiconductor layer L3 acts as a semiconductor layer for electrode material, the semiconductor layer L1 acts as an active layer, the semiconductor layer L2 acts as a semiconductor layer for electrode material, and the electrode E1 acts as a source electrode.
A semiconductor layer 3 is applied to the region between adjacent electrode elements 0 of the gate electrode G of the semiconductor layer L1 from the electrode E2 side, and a semiconductor layer L2 is applied to the region between the adjacent electrode elements 0 of the gate electrode G of the semiconductor layer L1. A current flows through the electrodes in order toward the electrode E1 side. In addition, if a DC power source with the electrode E1 side positive is connected between the electrodes E1 and 12, the electrode E1 is the drain electrode, the semiconductor layer L3 is the semiconductor layer for electrode material, the semiconductor layer L1 is the active layer, and the semiconductor layer L2 is the drain electrode. The semiconductor layer for electrode material, the electrode F2 acts as a source N pole, and the semiconductor layer [2
, the region between the adjacent electrode elements 0 of the gate electrode G of the semiconductor layer [1, and the semiconductor layer L3 in order, and a current flows toward the electrode E2 side. Furthermore, if a control I lightning voltage is applied between the electrode E1 or E2 and the gate electrode G, the control voltage is applied between the semiconductor layer L1 and the gate electrode G via the semiconductor layers L2 and Ll or the semiconductor layers L3 and Ll. Since it is applied across the Schottky junction J formed between the electrode element Q,
In the region between the adjacent electrode elements 0 of the gate electrode G of the semiconductor layer L1, the adjacent electrode elements Q of the semiconductor layer L1 and the gate electrode G are provided.
The depletion layer expanding from the Schottky junction J formed between (including cases), it expands. Therefore, according to the conventional Schottky junction field effect transistor shown in FIG. 1, a load is connected between electrodes E1 and 12 via a DC power supply, and
If a control voltage is applied between the control voltage and the gate electrode G, a current controlled according to the polarity and value of the control voltage (including when the value is zero) can be supplied to the load. A function as an effect transistor can be obtained. However, in the case of the conventional Schottky junction field effect transistor shown in FIG. 1, although it can function as a field effect transistor and has good high frequency characteristics, it has certain limitations. The reason is as follows. That is, in the case of the conventional Schottky junction field effect transistor shown in FIG. 1, its high frequency characteristic figure of merit f□ As described above, when the time taken for electrons to travel across the semiconductor layer L1 when a current flows through the semiconductor layer L1 is τ, it is expressed as f,=1/2πτ. Therefore, the shorter the time for electrons traveling across the semiconductor layer L1 to travel across the semiconductor layer L1, the better the high frequency characteristics are. However, in the case of the conventional Schottky junction field effect transistor shown in FIG.
When the current flowing through electrode 1 is a current flowing from the electrode E2 side to the electrode tIiEl side, the electrons traveling across the semiconductor layer L1 from the semiconductor layer L2 side to the semiconductor layer L3 side are applied between the electrodes E1 and 12. Due to the voltage of the DC power supply, the electric field generated in the semiconductor layer L1 causes the semiconductor layer L
However, since the semiconductor layer L1 is only connected to the semiconductor layer L2 having a low resistivity on the electrode E2 side, the semiconductor layer L1 is accelerated from the E2 side to the semiconductor layer L3 side. This is because the electrons traveling across the semiconductor layer L1 are only accelerated from a state where their initial velocity is zero, and therefore, in this case, it took half the time for the electrons to travel across the semiconductor layer L1. Further, as described above, when the current flowing through the semiconductor layer L1 is a current flowing from the electrode E1 side to the electrode E2 side, the electrons traveling across the semiconductor layer L1 from the semiconductor layer L3 side to the semiconductor layer L2 side are The electric field generated in the semiconductor layer L1 by the voltage of the DC power supply applied between E1 and E12 accelerates the semiconductor layer L2 from the semiconductor layer L3 side. Electrode E1
Since the semiconductor layer L2 having a low resistivity is only connected to the side, the electrons traveling across the semiconductor layer L1 are accelerated from the initial velocity of zero, as described above. Therefore, in this case as well, the semiconductor layer L
This is because it takes a relatively long time for electrons traveling across the semiconductor layer L1 to travel across the semiconductor layer L1. According to the object of the present invention, the present invention provides a field effect transistor having significantly better high frequency characteristics than the conventional Schottky junction field effect transistor described above in FIG. This paper aims to propose a new Schottky junction field effect transistor and its manufacturing method. DISCLOSURE OF THE INVENTION According to the Schottky junction field effect transistor according to the present invention, as in the case of the conventional Schottky junction field effect transistor described above in FIG. A first semiconductor layer having an opposite second conductivity type and a relatively high specific resistance, and arranged within the first semiconductor layer at a required interval in a direction along the surface of the first semiconductor layer. A gate electrode having a plurality of electrode elements formed therein and forming a Schottky junction with the first semiconductor layer is buried; A first electrode is formed with or without a second semiconductor layer having the same conductivity type as the semiconductor layer and a relatively low resistivity, and a first electrode is further formed on the other surface of the first semiconductor layer. The second electrode is formed with or without a third semiconductor layer having the same conductivity type as the first semiconductor layer and a relatively low resistivity. However, in the Schottky junction field effect transistor according to the present invention, there is a gap between the first semiconductor layer and the second semiconductor layer or the first electrode, or between the Ml semiconductor layer and the third semiconductor layer or the second electrode. has the same conductivity type as the first semiconductor layer and has a relatively low resistivity, and the first semiconductor layer has the first conductivity type or the second conductivity type. Depending on whether the first semiconductor layer side has a conduction band bottom higher than that of the first semiconductor layer or a valence band top lower than that of the first semiconductor layer, A fourth semiconductor layer is inserted therein. According to the Schottky junction field effect transistor according to the present invention, as in the case of the conventional Schottky junction field effect transistor described above in FIG. If a load is connected to the gate electrode and a control voltage is applied between the first or second electrode and the gate electrode, a current will be controlled according to the polarity and value of the control voltage (even if the value is zero). ) can be supplied to the load as a field effect transistor. Also, as in the case of the conventional Schottky junction field effect transistor described above in FIG. 1, when a current flows across the first semiconductor layer, electrons traveling across the first semiconductor layer As in the case of the conventional Schottky junction field effect transistor, which reached 100 in FIG. is accelerated by However, in the case of the Schottky junction field effect transistor according to the present invention, between the first semiconductor layer and the second semiconductor layer or the first electrode, or between the first semiconductor layer and the third
or the second electrode, the first semiconductor layer has the same conductivity type as the first semiconductor layer and has a relatively low specific resistance, and the first semiconductor layer has the first conductivity type. On the first semiconductor layer side, the bottom of the conduction band is higher than that of the first semiconductor layer, or the bottom of the conduction band is higher than that of the first semiconductor layer, depending on whether the semiconductor layer has the conductivity type or the second conductivity type. Since the fourth semiconductor layer having a low valence band peak is inserted, electrons or holes from the fourth semiconductor layer are transferred to the first semiconductor layer side of the fourth semiconductor layer. The electron beam enters the first semiconductor layer with energy depending on the difference between the bottom of the conduction band or the top of the valence band between the electron beam and the first semiconductor layer, and is accelerated within the first semiconductor layer. Therefore, the time taken for electrons or holes to travel across the first semiconductor layer is
Since it is much shorter than the conventional Schottky junction field effect transistor described above in FIG. 1, the function as a field effect transistor is It has the characteristic that it can be obtained as having significantly better high frequency characteristics compared to the conventional method. Further, according to the first manufacturing method of the Schottky junction field effect transistor according to the present invention, the Schottky junction field effect transistor has a first conductivity type or a second conductivity type opposite to the first conductivity type, and has a relatively high specific resistance. A first Schottky junction is formed between the fifth semiconductor layer and the fifth semiconductor layer, and a plurality of electrode elements arranged at required intervals in the direction along the surface of the fifth semiconductor layer. A process of forming a gate electrode having the same conductivity type as the fifth semiconductor layer and a relatively high specific resistance, and embedding a gate N pole to form the gate electrode. a sixth semiconductor layer forming a second Schottky junction therebetween, burying the gate electrode, and forming a Schottky junction consisting of the first and second Schottky junctions between the gate electrode and the gate electrode; a step of forming a first semiconductor layer consisting of a fifth and a sixth semiconductor layer having the same conductivity type and a relatively low resistivity on the first semiconductor layer; Depending on whether the semiconductor layer has the first conductivity type or the second conductivity type, the conduction band bottom on the first semiconductor layer side is higher than that of the first semiconductor layer. or forming a fourth semiconductor layer having a lower valence band peak than the first semiconductor layer. Further, according to the second manufacturing method of the Schottky junction field effect transistor according to the present invention, the Schottky junction field effect transistor has a first conductivity type or a second conductivity type opposite to the first conductivity type, and has a relatively low specific resistance. forming a fourth semiconductor layer having the same conductivity type and relatively low resistivity on the third semiconductor layer having the same conductivity type; In addition, the third semiconductor of the fourth semiconductor layer has a relatively high specific resistance, and depending on whether the fourth semiconductor layer has the first conductivity type or the second conductivity type. The layer side has a lower conduction band bottom than the side opposite to the third semiconductor layer side, or the third semiconductor layer side of the fourth semiconductor layer has a higher valence band top than the side opposite to the third semiconductor layer side. a step of forming a fifth semiconductor layer; a step of forming a fifth semiconductor layer; a step of forming a gate electrode forming a first Schottky junction therebetween; and burying the gate electrode on a fifth semiconductor layer having the same conductivity type and relatively high resistivity. a sixth semiconductor layer forming a second Schottky junction with the gate electrode, burying the gate electrode and forming a first and second Schottky junction between the gate electrode; and forming a first semiconductor layer including fifth and sixth semiconductor layers forming a Schottky junction. According to the first and second manufacturing methods of the Schottky junction field effect transistor according to the present invention, the characteristic Schottky junction field effect transistor according to the present invention described above can be easily manufactured. have First, a preferred embodiment of the Schottky junction field effect transistor according to the present invention will be described. Example 1-1 FIG. 2 shows a first example of a Schottky junction field effect transistor according to the present invention. In FIG. 2, parts corresponding to those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted. A first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. It has a relatively low resistivity of 8 atoms/cm3 or more in terms of impurity concentration, and as shown in FIG. For example, A lx Ga1-x which has the bottom of the conduction band
It has the same structure as the conventional Schottky junction field effect transistor described above with reference to FIG. 1, except that a semiconductor layer L4 made of AS (0<X<1) is interposed. In this case, the difference ΔEc between the semiconductor layer L1 side of the semiconductor layer L4 and the semiconductor layer L4 side of the semiconductor layer L1 as seen at the bottom of the conduction band is, as shown in FIG. 4, AI Ga1. A.S.
It takes the value of x according to the value of x. The above is the configuration of the first embodiment of the Schottky junction field effect transistor according to the present invention. According to this configuration, except for the matters mentioned above, it has the same configuration as the conventional Schottky junction field effect transistor described above in FIG. As in the case of the conventional Schottky junction field effect transistor described above, a load is connected between electrodes E1 and 12 via a DC power supply, and electrode E1
Alternatively, by applying a control voltage between E2 and the gate electrode G, a current controlled according to the polarity and value of the control voltage can be supplied to the load. Further, according to the Schottky junction field effect transistor according to the present invention shown in FIG. 2, as in the case of the conventional Schottky junction field effect transistor described above in FIG.
When a current flows across the semiconductor layer L1, electrons traveling across the semiconductor layer L1 are transferred to the electrodes E1 and 12.
Acceleration is caused by an electric field generated within the semiconductor layer L1 by the voltage of the DC power supply applied between them. However, in the case of the Schottky junction field effect transistor according to the invention shown in FIG. A semiconductor layer L4 having a conduction band bottom higher than that of the semiconductor layer L1 on the semiconductor layer L1 side is inserted between the semiconductor layer L1 and the semiconductor layer L2.
, electrons enter the semiconductor layer L1 with energy corresponding to the difference ΔE in the bottom of the conduction band between the semiconductor layer L1 side of the semiconductor layer L4 and the semiconductor layer L1, and are accelerated within the semiconductor layer L1. . Therefore, the time between electrons traveling across the semiconductor layer L1 and between the FRs traveling across the semiconductor layer L1 is significantly shorter than in the case of the conventional Schottky junction field effect transistor described above in FIG. Therefore, it has the feature that it can function as a field effect transistor with much better high frequency characteristics than the conventional Schottky junction field effect transistor described above in FIG. . Example 1-2 Next, a second example of the Schottky junction field effect transistor according to the present invention will be described. The second embodiment of the Schottky junction field effect transistor according to the present invention has the structure of the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. semiconductor layer 1,
L2, [3 and L4 are p-type instead of n-type,
Accordingly, as shown in FIG. 3, the semiconductor layer L4 has a lower valence band peak on the semiconductor layer L1 side than on the semiconductor layer L1 side (the difference between them is 8E). The structure is similar to that of the first embodiment according to the invention shown in FIG. 2, except for the following. The above is the configuration of the second embodiment of the Schottky junction field effect transistor according to the present invention. According to the Schottky junction field effect transistor having such a configuration, it is the same as the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. 2, except for the matters mentioned above. Although a detailed explanation will be omitted since the structure is as follows, in accordance with the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. Semiconductor layer L1 with energy corresponding to the difference ΔEv of the bottom of the valence band between the semiconductor layer L1 side of L4 and the semiconductor layer L1.
and is accelerated within the semiconductor layer L1. Therefore, in the conventional Schottky junction field effect transistor described above in FIG. Since the time is significantly shorter than that of a Schottky junction field effect transistor in which the field effect transistor is p-type, it has the characteristic that it can function as a field effect transistor with good high frequency characteristics. Yutaka Tomonao Uni 3 Next, a third embodiment of the Schottky junction field effect transistor according to the present invention will be described. The third embodiment of the Schottky junction field effect transistor according to the present invention has the structure of the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. The structure is similar to that of the first embodiment of the present invention shown in FIG. 2, except that the semiconductor layer L2 is omitted. The above is the configuration of the second embodiment of the Schottky junction field effect transistor according to the present invention. According to the Schottky junction field effect transistor having such a configuration, it is the same as the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. 2, except for the matters mentioned above. The details are as follows. Although the description will be omitted, this embodiment is characterized in that the same effects as in the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. 2 can be obtained. Example 1-4 Next, a fourth example of the Schottky junction field effect transistor according to the present invention will be described. A fourth embodiment of the Schottky junction field effect transistor according to the present invention, as shown in FIG. 5, has the structure of the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. The semiconductor layer L4 is interposed between the semiconductor layers L1 and L3 instead of being interposed between the semiconductor layers L1 and L2.
It has the same configuration as the first embodiment according to the present invention shown in the figure. The above is the configuration of the fourth embodiment of the Schottky junction field effect transistor according to the present invention. According to the Schottky junction field effect transistor having such a configuration, it is the same as the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. 2, except for the matters mentioned above. Although a detailed explanation will be omitted, the Schottky junction field effect transistor according to the invention described above in FIG. This embodiment is characterized in that the same effects as in the first embodiment can be obtained. Next, a preferred embodiment of the method for manufacturing a Schottky junction field effect transistor according to the present invention will be described. Example 2-1 FIG. 6 shows an example of a method for manufacturing a Schottky junction field effect transistor according to the present invention for manufacturing the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. In FIG. 6, parts corresponding to those in FIG. 2 are designated by the same reference numerals, and detailed description thereof will be omitted. The embodiment of the method for manufacturing the Schottky junction field effect transistor according to the present invention shown in FIG. 6 involves the following sequential steps. That is, a semiconductor substrate made of GaAS (hereinafter referred to as semiconductor layer L3 for simplicity) is prepared as the semiconductor layer L3 (FIG. 6A). Then, on the semiconductor layer L3, a semiconductor layer L5, which is the half of the semiconductor layer [1 on the semiconductor layer L3 side], is formed of GaAS by a vapor phase growth method that is known per se. Figure B) Next, a gate electrode G is placed on the semiconductor layer L5, and a Schottky junction is formed between it and the semiconductor layer L5.
1 by a method known per se (FIG. 6C). Next, the semiconductor layer L3 of the semiconductor layer L1 is placed on the semiconductor layer L5.
The semiconductor layer [6, which is the half on the opposite side, is formed of GaAS by vapor phase epitaxy so as to form a Schottky junction j2 between it and the gate electrode G. A semiconductor layer L consisting of semiconductor layers L5 and L6, in which a gate electrode G is embedded and the above-mentioned Schottky junction is formed between the layer L3 and the gate electrode G.
1 (Fig. 6D). In this case, the vapor phase growth method uses a mixed gas of trimethyl gallium gas or triethyl gallium gas as a raw material gas, arsine (AsH3) gas as a raw material gas, and hydrogen as a carrier gas. The flow rate was set to 41/min, trimethyl gallium gas or triethyl gallium gas and alumin gas as source gases were set to 4 3 × 10 molar fraction and 3 × 10' molar fraction, respectively, to the mixed gas, and the temperature was set to 600 molar fraction. It is possible to use a vapor phase growth method at a temperature of ~700°C. Next, a semiconductor layer L4 is formed on the semiconductor layer L1 by vapor phase growth using A I Ga1-x As (O<x<1).
(Fig. 6E). In this case, the vapor phase growth method uses melimethylgallium gas or triethylgallium gas as a raw material gas, trimethylaluminum gas or triethylaluminum gas as a raw material gas, arsine gas as a raw material gas, and selenium as an n-type impurity gas. A mixed gas of hydrogen chloride gas and hydrogen as a carrier gas is used with a flow rate of hydrogen as a carrier gas of 41/min, trimethyl gallium gas or trimethyl gallium gas, trimethyl aluminum gas or triethyl aluminum gas as a raw material gas, and Arsine gas was added to the mixed gas at a mole fraction of 3 x 10, 2 x 10', 4 and 3 x 10 to 3 x 10', respectively, and hydrogen selenide gas was used as an n-type impurity gas. It is possible to use a vapor phase growth method with a mole fraction of 10-7 and a temperature of 600 to 700°C. Next, a semiconductor layer L2 made of GaAS is formed on the semiconductor layer F4 by a vapor phase growth method (FIG. 6F). The vapor phase growth method in this case may be the same vapor phase growth method as that used for forming the semiconductor layer L5. Next, an electrode E1 is placed on the surface of the semiconductor layer L2 opposite to the semiconductor layer F4 side and on the surface of the semiconductor layer L3 opposite to the semiconductor layer F1 side by a method known per se.
, and F2. In this way, the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. 2 is obtained. The above is an example of the manufacturing method of the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. According to this embodiment of the method for manufacturing a Schottky junction field effect transistor according to the present invention, as is clear from the above, the characteristic Schottky junction field effect transistor according to the present invention shown in FIG. It has the characteristic that field effect transistors can be easily manufactured. In addition, in this case, the semiconductor layers L6, F4, and F2 are treated with organic gallium gas (trimethyl gallium gas or triethyl gallium gas in the case of the above example), organic aluminum gas (trimethyl aluminum gas in the case of the above example), respectively, as described above. gas or triethylaluminum gas)
, and organic gallium gas (in the above example, trimethyl gallium gas or triethyl gallium gas), after forming the semiconductor layer L6, organic gallium gas is replaced with organic aluminum gas. The semiconductor layer L4 can be formed by simply adding
Furthermore, the semiconductor th layer L2 can be formed by simply stopping the use of organic aluminum gas after forming the semiconductor layer L4, so that the Schottky junction field effect transistor according to the present invention shown in FIG. It has the characteristic that it can be manufactured more easily. Example 2-2 Next, with reference to FIG. 7, a method for manufacturing a Schottky junction field effect transistor according to the present invention for manufacturing a fourth embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. 5 will be explained. Let's give an example. In FIG. 7, the same reference numerals as in FIG. 5 are used to omit detailed explanation. The embodiment of the method for manufacturing the Schottky junction field effect transistor according to the present invention shown in FIG. 7 involves the following sequential steps. That is, as in the case of Example 1-2 described above, a semiconductor substrate made of GaAS (hereinafter referred to as semiconductor layer L3 for simplicity) as semiconductor layer L3 is prepared (FIG. 7A). However, on the semiconductor layer F3, the semiconductor layer L4 is formed of Alx Ga1-x As (Q<x1) by the vapor phase growth method, as in the case of Example 2-1 described above. (FIG. 7B) Next, a semiconductor layer L5 is formed on the semiconductor layer F5 in the same manner as in Example 2-1 described above (FIG. 7C). Next, a gate electrode G is formed on the semiconductor layer F5 in Example 2-
It is formed in the same manner as in case 1 (FIG. 7D). Next, a semiconductor layer L6 is formed on the semiconductor layer F5 in Example 2-
A semiconductor layer L1 is formed in the same manner as in case 1, thus burying the gate electrode G and forming a Schottky junction J with the gate electrode G (FIG. 7E). Next, a semiconductor layer L2 is formed on the semiconductor layer F1 in the same manner as in Example 2-1 described above (FIG. 7F). Next, electrodes E1 and F2 are provided on the surface of the semiconductor layer L2 opposite to the semiconductor layer F1 side, and on the surface of the semiconductor layer L3 opposite to the semiconductor layer F4 side, respectively.
It is formed in the same way as in the case of -1. In this way, a fourth embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. 5 is obtained. The above is an example of the manufacturing method of the fourth embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. According to this embodiment of the method for manufacturing a Schottky junction field effect transistor according to the present invention, as is clear from the above, the characteristic Schottky junction field effect transistor according to the present invention shown in FIG. It has the characteristic that field effect transistors can be easily manufactured. In addition, in the above description, only four embodiments of the Schottky junction field effect transistor according to the present invention have been shown, and two embodiments have been shown regarding the manufacturing method of the Schottky junction field effect transistor according to the present invention. For example, the semiconductor layers L1, L2 and 3 are I n
Without departing from the spirit of the present invention, each of the Schottky junction field effect transistor and its manufacturing method according to the present invention may be made of a GaAs-based or InGaASP-based material, and in this case, the semiconductor layer L4 may be made of InP. , various modifications and changes may be made. 4. Brief Description of the Drawings FIG. 1 is a cross-sectional view showing a conventional Schottky junction field effect transistor. FIG. 2 is a cross-sectional view showing a first embodiment of a Schottky junction field effect transistor according to the present invention. FIG. 3 is an energy band diagram of the semiconductor layers L1 and L4 in the first embodiment of the Schottky junction field effect transistor according to the present invention shown in FIG. FIG. 4 shows, in accordance with FIG. 2, the X FIG. 3 is a diagram showing the difference ΔE0 between the conduction band bottoms between the semiconductor layers L4 and 11 with respect to FIG. FIG. 5 is a cross-sectional view showing a fourth embodiment of the Schottky junction field effect transistor according to the present invention. FIG. 6 shows a route in sequential steps showing an embodiment of a method for manufacturing a Schottky junction field effect transistor according to the present invention for manufacturing a first embodiment of a Schottky junction field effect transistor according to the present invention shown in FIG. FIG. FIG. 7 shows a route in sequential steps illustrating an embodiment of a method for manufacturing a Schottky junction field effect transistor according to the present invention for manufacturing a fourth embodiment of a Schottky junction field effect transistor according to the present invention shown in FIG. FIG. 1 to [4... Semiconductor layer 15, L6... Semiconductor layer G constituting semiconductor layer L1......・Gate electrode 0
・・・・・・・・・・・・・・・ Electrode element J of gate electrode 0, j1. j2 ・・・・・・・・・・・・・・・Schottky junction E1. E2・・・・・・Electrode applicant Nippon Telegraph and Telephone Public Corporation

Claims (1)

[Claims] 1. A first semiconductor layer having a first conductivity type or a second conductivity type opposite to the first conductivity type and having a relatively high specific resistance; The first semiconductor layer has a plurality of electrode elements arranged at required intervals in the direction along the surface thereof, and forms a Schottky junction with the first semiconductor layer. A gate electrode is buried on one surface of the first semiconductor layer through or through a second semiconductor layer that has the same conductivity type as the first semiconductor layer and has a relatively low specific resistance. a third semiconductor layer having the same conductivity type as the first semiconductor layer and a relatively low specific resistance on the other surface of the first semiconductor layer; In a Schottky junction field effect transistor in which a second electrode is formed with or without intervening, between the first semiconductor layer and the second semiconductor layer or the first electrode, or between the first semiconductor layer and the second semiconductor layer or the first electrode; the first semiconductor layer and the third semiconductor layer;
or the second electrode, the first semiconductor layer has the same conductivity type as the first semiconductor layer and has a relatively low resistivity, and the first semiconductor layer has the first conductivity type. The first semiconductor layer side has a conduction band bottom higher than that of the first semiconductor layer, or has a conduction band bottom higher than that of the first semiconductor layer, or A Schottky junction field effect transistor characterized in that a fourth semiconductor layer having a valence band peak lower than that of the semiconductor layer is interposed. 2. On the fifth semiconductor layer having the first conductivity type or a second conductivity type opposite to the first conductivity type and having a relatively high specific resistance, a required interval is formed in the direction along the surface of the fifth semiconductor layer. a step of forming a gate electrode having a plurality of electrode elements arranged so as to maintain the same and forming a first Schottky junction with the fifth semiconductor layer; and a sixth semiconductor having the same conductivity type and relatively high resistivity, and embedding the gate electrode to form a second Schottky junction with the gate electrode. forming a layer, burying the gate electrode and interfacing the first layer with the gate electrode;
and a second Schottky junction, forming a first semiconductor layer composed of the fifth and sixth semiconductor layers forming a Schottky junction, and forming a first semiconductor layer of the same conductivity type as the fifth and sixth semiconductor layers on the first semiconductor layer. and has a relatively low specific resistance, depending on whether the first semiconductor layer has a first conductivity type or a second conductivity type. forming a fourth semiconductor layer having a conduction band bottom higher than that of the first semiconductor layer or having a valence band top lower than that of the first semiconductor layer; A method for manufacturing a Schottky junction field effect transistor, comprising the steps of: 3. In the method for manufacturing a Schottky junction field effect transistor according to claim 2, in the step of forming the sixth semiconductor layer, the sixth semiconductor layer is formed into a semiconductor layer made of GaAS by a vapor phase growth method. and forming the fourth semiconductor layer, the step of forming the fourth semiconductor layer.
A method for manufacturing a Schottky junction field effect transistor, characterized in that a semiconductor layer of AlxGa and XAs (Q<X≦1) is formed by a vapor phase growth method using organic aluminum gas. 4. A method for manufacturing a Schottky junction field effect transistor according to claim 3, characterized in that trimedel aluminum gas or triethyl aluminum gas is used as the organic aluminum gas. 5. On a third semiconductor layer having a first conductivity type or a second conductivity type opposite to the first conductivity type and having a relatively low specific resistance, a layer having the same conductivity type as the first conductivity type and a comparatively low resistivity. forming a fourth semiconductor layer having a relatively low specific resistance, and having the same conductivity type as the fourth semiconductor layer and a relatively high specific resistance; The bottom of the conduction band is lower than that on the side of the fourth semiconductor layer opposite to the third semiconductor layer, depending on whether the fourth semiconductor layer has the first conductivity type or the second conductivity type. or having a higher valence band peak than the side of the fourth semiconductor layer opposite to the third semiconductor layer; A first Schottky junction is formed between the fifth semiconductor layer and the fifth semiconductor layer, having a plurality of electrode elements arranged at required intervals in the direction along the surface of the fifth semiconductor layer. a step of forming a gate electrode having the same conductivity type as the fifth semiconductor layer and a relatively high specific resistance, and burying the gate electrode between the fifth semiconductor layer and the fifth semiconductor layer; forming a sixth semiconductor layer forming a second Schottky junction, burying the gate electrode and forming a Schottky junction consisting of the first and second Schottky junctions between the sixth semiconductor layer and the gate electrode; forming a first semiconductor layer made up of the fifth and sixth semiconductor layers. 6. In the method for manufacturing a Schottky junction field effect transistor according to claim 5, in the step of forming the fourth semiconductor layer, the fourth semiconductor layer is formed by vapor phase growth using organic aluminum gas. By law, Atx
In the step of forming the fifth semiconductor layer, the fifth semiconductor layer is formed into a semiconductor layer made of GaAS by vapor phase epitaxy. In the step of forming the sixth semiconductor layer, the sixth semiconductor layer is formed by vapor phase epitaxy.
A method for manufacturing a Schottky junction field effect transistor, characterized in that it is formed in a semiconductor layer made of GaAs. 7. A method for manufacturing a Schottky junction field effect transistor according to claim 6, characterized in that a trimedel aluminum gas is used as the organic aluminum gas.