JPS5848468A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain uniform active semiconductor layers by forming the active semiconductor layers constituting two field effect transistors by the same semiconductors with the same thickness and the same impurity concentration. CONSTITUTION:The active semiconductor layer 1A which constitutes the field effect transistor 8A and the active semiconductor layer 1B which constitutes the field effect transistor 11B are formed by the same semiconductors under the conditions with the same thickness, the same impurity concentration, and the like. However, the gate electrode 6A of the field effect transistor 8A and the gate electrode 6B of the field effect transistor 11B are made of different gate electrode materials. A Schottky junciton 7A is formed between the gate electrode 6A and the active semiconductor layer 1A, and a homogenious P-N junction 10B is formed between the gate electrode 9B and the active semiconductor layer 1B. Therefore, the Schottky junction 7A and the homogeneous P-N junction 10B have the different heights of barriers. Thus the field effect transistors 8A and 11B have different pinchoff voltages.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides that at least a first and a second semiconductor active layer are formed on a common insulating-semiconductor substrate; A source electrode of W41 and a drain electrode of IRl are electrically connected to the semiconductor active layer of IR1 on the side opposite to the semi-insulating semiconductor substrate side, and To form a Schottky junction or a PN junction with the first semiconductor active layer between the first source electrode and the first drain electrode on the side opposite to the insulating semiconductor substrate side. A first field effect transistor is formed including the gate-pole of W41 connected to the second semiconductor active layer and the semiconductor active layer of M2, on the opposite side from the semi-insulating semiconductor base & a second source electrode and a second drain electrode that are ohically connected to each other; and the second semiconductor capacitor vIp1.
1. A Schottky junction or a PN junction is formed between the second source electrode and the drain electrode of the wire 2 on the side opposite to the semi-insulating semiconductor substrate and the second semiconductor active layer. The present invention relates to an improvement in a semiconductor device having a configuration in which a second field effect transistor includes a second gate electrode connected to form a junction and has a pinch-off voltage different from that of the first field effect transistor.

In the conventional sandalwood semiconductor device, the first gate electrode of the first field effect transistor and the second gate electrode of the tJ42 field effect transistor are formed of the same gate electrode material, so that 1 and #! The Schottky junctions or PN junctions of the two field effect transistors have the same barrier height, but the tenth field effect transistor of the first field effect transistor has the same barrier height.
) Even if the semiconductor active layer and the second semiconductor active layer of the second field effect transistor are formed of the same semiconductor, the first and *2 semiconductor active layers may have different thicknesses or different impurity concentrations. It is common that the field effect transistors have different pinch-off voltages, i.e., the first gate electrode of the second field effect transistor and the second gate electrode of the second field effect transistor. are made of the same material for the gate 11L pole, but
Even though the first semiconductor active layer of the charge effect transistor of J741 and the second semiconductor active layer of the second charge effect transistor are made of the same semiconductor, by having the true *g+, In the case where the first and second field effect transistors have different pinch-off voltages, it is common to have the configuration described below with reference to FIG. 1 or #42.

First of all, referring to the structure shown in FIG.
They are formed on a semi-insulating semiconductor substrate 2, separated from each other by sequential mesa etching portions 5 formed by mesa etching. In this case, the semiconductor active layers 1 and 1B are made of the same semiconductor, for example GaAs.
Although they are formed of and have the same impurity #1 degree, they have different densities Da and Db. In fact, the semiconductor active layer 1 is located in a semi-insulating semiconductor substrate, 2 whose main layer is N! from the opposite side! I
I implanting impurity ions #! The semiconductor active layer 1B is formed by implanting NWi impurity ions into the semi-insulating semiconductor substrate 2 from the main surface side as the first impurity, and impurity ions different from those during the ion implantation process. The impurity ions are formed by a second impurity ion implantation process in which the impurity ions are implanted at an acceleration voltage of .

Further, a source electrode 4A and a drain electrode 5A made of metal, for example, are electrically connected to one semiconductor active layer on the opposite side from the semi-insulating semiconductor substrate 21m. In one semiconductor active layer, a source electrode 4A and a drain electrode [1i5A on the side opposite to the semi-insulating semiconductor substrate 2II]
In between, a gate IIL pole 6, for example M, is connected to form a semiconductor active junction 7A. A Schottky junction field effect transistor 8A is constituted by the semiconductor active layer 1, the source electrode 4A, the drain electrode 5A, and the gate electrode 6A.

Furthermore, a source electrode 4B and a drain electrode 5B made of the same metal as the four source electrodes and the drain electrode 5A of the field effect transistor 8A are ohmically connected to the semiconductor active layer 1B on the opposite side from the semi-insulating semiconductor substrate 211. has been done. In addition, between the source electrode 1i4B and the drain electrode 5B on the opposite side of the semiconductor active layer IBJζ semi-insulating semi-insulating semiconductor substrate, a gate electrode 6B made of the same metal as the six gate electrodes of the field effect transistor 8A is a semiconductor substrate. A Schottky junction 7B having the same barrier height as the Schottky junction 7A of the field effect transistor &A is connected to the active layer 1B.
are connected to form a Therefore, the semiconductor active layer 1B
.

A Schottky junction field effect transistor 8B is constituted by the source 1lll:1k4B,) and 4in[5BAc)g) electrode 6B.

Next, to describe the configuration of FIG. 2, the same semiconductor active layer 1 and 1B as in the case of FIG. 1 are placed on the same semi-insulating semiconductor substrate 2 as in the case of FIG. Similarly, they are separated and juxtaposed by mesa etching s3.

Furthermore, four source electrodes and a drain electrode 5A similar to the case shown in FIG. 111 are connected to one semiconductor active layer. However, between one semiconductor active layer and four source electrodes and four drain electrodes 5A on the opposite side from the semi-insulating semiconductor substrate 211, for example, a gate electrode 9A made of (hAs) is connected to one semiconductor active layer. Between PNlii' and 1
0A is connected to synthesize 0A. The PN junction field effect transistor 11 includes the semiconductor active layer IA, the source electrode 4A, the drain electrode 5A, and the gate electrode 9A.
A is configured.

Further, a source electrode 4B and a drain electrode 5B, similar to those in Figure #11, are connected to the semiconductor active layer 1B in an ohmic manner. However, in the semiconductor active layer 1B, there is a field effect transistor 1 between the source electrode 4p and the drain 11IL pole 5B on the opposite side from the semi-insulating semiconductor substrate &211.
Gate electrode 9 made of the same semiconductor as gate electrode 9A of 1A
B has the same wall thickness as the PN junction 10A of the field effect transistor 11A between it and the semiconductor active layer 1B.
They are connected to form a junction 10B. Thus, the semiconductor active layer IB, the source electrode 4B, and the drain electrode 5B
and a PN junction field effect transistor 11. including the gate 'vL pole 9B. +B is configured.

In Figure 11 and Figure t42 above, the first field effect transistor (8A in Figure 1, 11 in Figure 92)
(6A in case of #!1-, 9 in case of Fig. 2) and a field effect transistor of t142 (8B in case of Fig. 1, 11 B in case of Fig. 2) noaR2 (7) gate electrode (#! 6B for Figure 1 9B for Figure 2) and -
It is made of the same electrode material, but #! The semiconductor active layer of the field effect transistor 1 (1A in both FIGS. 1 and 2) and the second semiconductor active layer of the field effect transistor 2 (1A in both FIGS. 1 and 2) In the case of I
B) and W42 are made of the same semiconductor but have different thicknesses, Da and Db), so that the field effect transistors wil and W42 have different pinch-off voltages. A conventional semiconductor device has been revealed. The fact that the first and second field effect transistors have different pinch-off voltages means that the first and second field effect transistors have different pinch-off voltages.
In the case shown in the figure, when applying a voltage that gradually increases in value between the four source electrodes and the gate IIE electrode 6A of the first field effect transistor 8A, the voltage spreads from the Schottky junction 7A to the semi-insulating semiconductor base &2 The source electrode 4A when the depletion layer 12A reaches the semi-insulating semiconductor substrate 2 and the four source electrodes and the drain electrode 5A become non-conductive.
When applying a voltage that gradually increases in value between the voltage between the gate electrode 6 and the source electrode 4B and the gate electrode 6B of the second field effect transistor 8B, the Schottky junction 7F! The depletion layer 12B extending from h to the semi-insulating semiconductor substrate 2 side reaches the semi-insulating semiconductor substrate 2, thereby causing a non-conducting state between the source electrode 4B, the drain electrode, and the source electrode Wa4B and the gate electrode 5B. 6
This means that the voltage between B and B is different. In the case of FIG. 2, the source electrode 4 of the first field effect transistor 11A
When applying a voltage that gradually increases in value i between A and the gate electrode 9A, the depletion layer 15A that spreads from the PN junction 10A to the semi-insulating semiconductor substrate 211il reaches the semi-insulating semiconductor substrate 2, thereby , the voltage between the source electrode 4A and the gate electrode 9A when the source electrode 4A and the drain electrode 5A become non-conductive, and the voltage between the source electrode 4B and the gate electrode 9B of the second field effect transistor 11B gradually change. When applying a voltage that increases, the depletion layer 1 spreads from the PN-junction 10B to the insulating semiconductor substrate &211.
3B reaches the semi-insulating semiconductor substrate 2, which means that the voltage between the source electrode 4B and the gate 1498 is different when the source electrode 4B and the drain electrode 5, B become non-conductive.

However, in the case of the conventional semiconductor device described above in FIGS. 1 and tR2, one first semiconductor active layer forming the first field effect transistor and one second semiconductor forming the second field effect transistor The active layer 1B has a different thickness Da.
and Db, it is necessary to form each separately, (
For this reason, many steps were performed to obtain s1 and the second semiconductor active layer.Also, the first and second semiconductor active layers 1 and 1B had mutually different thicknesses Da and 10". Db,
It took some time to obtain the desired values evenly, and therefore it was difficult to obtain the first and second field effect transistors having the desired characteristics. Furthermore, in the case where the first and second semiconductor active layers and 1B are formed by impurity ion implantation treatment as shown above, high-temperature aninyl treatment is required. This method had disadvantages such as simulating many more steps to obtain 1B and 1B.

Incidentally, in the above description, #! of the first field effect transistor is described with reference to FIGS. The first gate electrode of the first field effect transistor and the second gate electrode of the second field effect transistor are formed of the same gate electrode material, but the first semiconductor active layer of the first field effect transistor and the second gate electrode of the second field effect transistor are Even though the 182 semiconductor active layers of the effect transistor are made of the same semiconductor, they have different thicknesses, so that #! The disadvantages of the conventional semiconductor device when the first and second field effect transistors are provided with different pinch-off voltages have been described. 1 gate electrode and #! of the second field effect transistor. The gate electrodes of the field effect transistors 1 and 2 are made of the same gate electrode material;
Although the auxiliary layer and the second semiconductor active layer of the second field effect transistor are made of the same semiconductor, they have different impurity concentrations, so that the first and second field effect transistors have different pinch-off voltages. In the case of a conventional semiconductor device having a first semiconductor active layer constituting a first field effect transistor and a second semiconductor active layer constituting a second field effect transistor, although a detailed description thereof will be omitted, It is necessary to separately form semiconductor active layers having different impurity concentrations, and there are also drawbacks such as difficulty in obtaining different impurity concentrations at desired values.

Therefore, the present invention provides a novel wI1g1 without the above-mentioned drawbacks.
This will become clear from the detailed description below.

Figure W43 shows a first embodiment of the semiconductor device according to the present invention, and Figures 1 and #! The same reference numerals are given to the parts in both FIGS. 2 and 2, and a detailed explanation thereof will be omitted.
As in the case of FIG. 1, they are formed on a semi-insulating semiconductor substrate 2 similar to that shown in the figure, separated from each other by mesa etching portions 3 and juxtaposed. However, in this case, the semiconductor active layers 1 and 1B are made of the same semiconductor, for example, GaAs.
and are formed under the same conditions of the same thickness and impurity count.

In practice, the semiconductor active layers 1 and 1B are formed primarily by forming one uniform semiconductor layer on the semi-insulating semiconductor substrate 2 by an epitaxial growth method, and then forming a mesa layer on the semiconductor layer. It is formed by performing an etching process to form etching s3.

Further, in the semiconductor active layer 1A, on the side opposite to the semi-insulating semiconductor substrate 211, the first and! ! Four source electrodes and a drain electrode 5A similar to the case shown in FIG. 42 are ohmically connected. Furthermore, for each semiconductor active layer, between the four source electrodes on the opposite side of the semi-insulating semiconductor substrate 2@ and the drain electrode 5A, there are six gate electrodes made of the same metal as in the case of Figure #11. However, between one semiconductor active layer! @1
They are connected to form a seat joint 7A similar to that shown. Therefore, Ushihiro body support layer IA, source electrode 4A
1 The first electrode including the drain electrode 5A and the gate electrode 6A
A Noschottky junction field effect transistor 8A is constructed as in the case shown in the figure.

Furthermore, on the side opposite to the semi-insulating semiconductor substrate 211, a saw λ similar to that in FIGS. 1 and 2 is placed on the semiconductor active layer 1B.
The electrode 4B and the drain electrode 5B are ohmically connected. Further, a semi-insulating semiconductor substrate 2 is provided on the semiconductor active layer 1B.
- On the side opposite to the source λ electrode 4B and the drain electrode 5B, a semiconductor active layer 1 similar to that in FIG.
Between the gate electrode 9B made of the same semiconductor as B and the semiconductor active layer 1B, there is a PN@coupling 10B in the same manner as in the case of FIG.
are connected to form a Therefore, the semiconductor active layer IB
A PN junction field effect transistor 11B similar to that shown in FIG. 2 is constructed including a source electrode 4B, a drain electrode 5B, and a gate electrode 9B. In this case, P
Semiconductor active layer 1 of N-junction field effect transistor 11B
The region under the gate electrode 9B of B has the same conditions such as thickness and impurity concentration as the region under the gate electrode 6A of the semiconductor active layer IA of the Schottky junction field effect transistor 8A.

The above is the configuration of the first embodiment of the semiconductor device according to the present invention. According to this configuration, one semiconductor active layer and one field effect transistor constitute eight field effect transistors.
The semiconductor active layer 1B constituting the semiconductor active layer 1B is made of the same semiconductor and is formed under the same conditions such as the same thickness and impurity concentration, but the gate electrode 6A of the eight field effect transistors and the gate electrode 9B of the field effect transistor 11B are different. A field effect transistor 8 is formed of a gate electrode material, and 1 is formed of a gate electrode material.
The gate electrode 6 of the semiconductor active layer forms a Schottky junction with the semiconductor active layer, and the field effect transistor 11B
The dirt electrode 9B is homo-PN between the semiconductor active layer 1B
Schottky junction 7 is formed by forming junction 10B.
Humans and homo-PN junction 10B have different barrier heights. The 8 field effect transistors and 11B have different pinch-off voltages. For example, semiconductor active layer 1
1B and 1B are both made of GaAg, and both have a thickness of 120 OL impurity #If is 1X 1Q ” al-
'Then, the 6 gate electrodes are AI! When the gate electrode 9B is made of Ga-containing 3, the Schottky junction 7 is α
8■, the PN' junction 10B has a barrier height of 1.4■, and the 8 field effect transistors have -0.2V, "tl"
ll effect) Run') x911 B +2. It has a pinch-off voltage of OV.

Accordingly, the semiconductor device according to the present invention shown in FIG. 1m3 has a configuration in which two field effect transistors having different pinch-off voltages are formed, as in the case of FIGS. w41 and 42. However, the semiconductor active layers 1 and 1B that constitute the two field effect transistors
Since they are formed of the same semiconductor and under the same conditions such as thickness and impurity concentration, they are
of#! Unlike the conventional cases shown in FIGS. 1 and 21, it is not necessary to form each semiconductor active layer separately.
It has great features such as being able to be obtained more easily and uniformly than in the case of FIGS. 1 and 2, and without the drawbacks mentioned above in FIGS. 1 and 2-.

Next, a second embodiment of the semiconductor device according to the present invention will be described with reference to FIG. 4. Parts corresponding to those in FIG. In the above-mentioned structure, the semiconductor active layer 1B is connected to the gate electrode 9B made of the same semiconductor so as to form a homogeneous PN@contact 10B with the semiconductor active layer 1B. The PN junction W tortoise field effect transistor 11B has a semiconductor substrate auxiliary layer 1B made of GaAs, for example.
) is replaced with a hetero PN junction field effect transistor 11B' having a structure in which the gate electrode fI9B' made of a semiconductor represented by 1B is connected to form a heterojunction IQB' with the semiconductor active layer 1B. Except for the third
It has the same configuration as the case shown in the figure.

The above is the configuration of the second embodiment of the semiconductor device according to the present invention, and this configuration is the same as that shown in FIG. 3 except for the matters mentioned above, and the Schottky junction 7A and It is clear that the heterojunction 10B' has a different barrier height. For this reason, the field effect transistors 8 and 11B' have different pinch-off voltages.

Accordingly, the semiconductor device according to the present invention described above with reference to FIG. 4 has a configuration in which two field effect transistors having mutually different pinch-off voltages are formed, as in the case of FIG. 3. However, since the semiconductor active layers 1 and 1B constituting the two field effect transistors are made of the same semiconductor and are formed under the same conditions such as the same thickness and impurity concentration as in the case of the 6th case, in the case of fig. It has the same excellent characteristics.

Next, with reference to FIG. 5, IJ! of the semiconductor device according to the present invention!
Embodiment 3 will be described. Parts corresponding to those in FIG. 6 and FIG. For example, a Schottky junction field effect transistor 8A has a configuration in which six gate electrodes made of gold maple per layer are connected to one semiconductor active layer to form seven Schottky junctions.
) aAs semiconductor active layer, for example, a different semiconductor active layer -! A heterostructure in which a gate electrode 9B' made of a semiconductor represented by t-, Aa (0<x<1) is connected to form a heterojunction 10B' with a semiconductor active layer 1B. It has the same structure as the case of FIG. 3 except that it is replaced with a PN junction m field effect transistor 11B'.

The above is the configuration of the third embodiment of the semiconductor device according to the present invention. According to this configuration, it is the same as the case of FIG. 1
Since it is clear that 0B' and homo PN@10B have different barrier heights, field effect transistors 11B' and 11B have different pinch-off voltages, and in this case also one semiconductor active layer. and 1B are made of the same semiconductor, have the same thickness, and are formed under the conditions of impurity #I & storm force, so #! It has the same excellent features as the case in Figure 3.

Next, with reference to FIG. 6, #I4 of the semiconductor device according to the present invention
To describe the embodiment, the same reference numerals are given to the parts corresponding to those in FIG. 5, and detailed explanation thereof is omitted. However, in the configuration described above in FIG. The gate electrode 9B should form a homo-PNg junction field effect transistor 10B with the semiconductor active layer 1B.
The semiconductor active layer 1B is made of As.
For example, GhN, -yAa (where 0<y<1, x''
A gate electrode made of a semiconductor represented by qy )? Bl
is replaced with a heterojunction field effect transistor 11Bl configured to be connected to the semiconductor active layer 1B to form a heterojunction 10B' having a barrier height different from that of the heterojunction 10B'. 5th except becoming
It has the same configuration as the case shown in the figure.

The above is the configuration of the embodiment of the semiconductor device wA4 according to the present invention. According to this configuration, it is the same as the case of FIG. ' and 11B# have different pinch-off voltages, and in this case as well, the semiconductor active layers 1 and 1B are made of the same semiconductor and are formed under the same thickness and impurity concentration conditions. It has excellent characteristics.

It should be noted that the foregoing has described only a few embodiments of the invention, and various modifications may be made without departing from the spirit of the invention.

[Brief explanation of the drawing]

#11 figure and @2 figure are line cross-sectional views showing conventional semiconductor devices, w45 figure, I! 4, 5, and 6 are cross-sectional views showing the first, second, tail 3, and fourth embodiments of the present invention, respectively. Among the layers, IA and 1B are semiconductor active layers, 2 is a semi-insulating semiconductor substrate, 4A and 4B are source electrodes, 5A and 5B are drain electrodes, and 6A16B. 9A, 9B, 9B' and 9BI are gate electrodes, 7mm and 7B are Schottky junctions, 10A, 10B. 10B' and 10B' are heterozygous, 8A, 8B111
B111B' and 11B# indicate field effect transistors, respectively. Applicant: Nippon Telegraph/Wtcho Corporation

Claims (1)

[Claims] At least a first and a second semiconductor active layer are formed on a common semi-insulating semiconductor substrate, and the semiconductor active layer of W41 and the first semiconductor active layer are formed on a common semi-insulating semiconductor substrate. , the source electrode and the first drain electrode of the turtle 1 are ohmically connected on the side opposite to the semi-insulating semiconductor substrate @ side, and the first
In the semiconductor active layer of ゛, the first source electrode on the semi-insulating semiconductor substrate side and the opposite side ゛ and the above all
Between the drain electrodes of w! a first gate electrode coupled to form a Schottky junction or PN junction with the first semiconductor active layer; the second semiconductor active layer; Copper plating 2
a second source electrode and a second drain electrode connected to the semiconductor active layer on the side opposite to the semi-insulating semiconductor substrate; A connection is made between the second source electrode and the second drain electrode on the side opposite to the semiconductor substrate 111 to form a Schottky junction or a PN junction with the second semiconductor active layer. and a second gate electrode to provide the tJ
In a semiconductor device having a configuration in which a Wj42 field effect transistor having a different pinch-off voltage from that of the Wj41 field effect transistor is configured, the above m1 and #1
the two semiconductor active layers are made of the same first semiconductor and have the same thickness;
formed under conditions such as impurity 11R, selected from the first semiconductor, a second semiconductor different from the first semiconductor, a third semiconductor different from the first and second semiconductors, and a metal. One of them is the material for the first gate electrode, and the other one is #! When the gate electrode material of No. 2 is used, the first gate electrode of the first field effect transistor and the second gate electrode of the field effect transistor are
2, the region under the first gate electrode of the first semiconductor active layer and the region under the second gate electrode of the second semiconductor active layer are the same. A semiconductor device characterized by having certain conditions such as thickness and impurity concentration.