JPS6150376A - Semiconductor device and integrated circuit thereof - Google Patents

Abstract

PURPOSE:To effect the implantation from the opposite region to the semiconductor region effectively by selecting the material in which the barrier of thin film seen from the semiconductor is high for the carrier of opposite polarity to that of the main carrier and the barrier of thin film seen from the opposite region is lower for the main carrier. CONSTITUTION:When a metallic thin film, e.g., of aluminum as an opposite region 10, an insulating film, e.g., clean SiO2 film of about 30Angstrom as a thin film 1, and Si single crystal including phosphorus atoms of 10<17> pieces/cm<3> as a semiconductor region are used, the positive holes produced by the high-energy carriers implanted from the opposite region 10 are gathered by the p type semiconductor region 101B which is arranged within the reach distance of diffusion drift of the holes with being in contact with the n type semiconductor region 100. Consequently a positive potential can be taken out from the region 101B altough a negative bias has been applied to the opposite region 10. In addition to the functions of light accepting and emitting, thus the device can be used at the same time for the power source being capable of reversal of polarity and comprising the characteristics shown in the figure.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to direct tunneling, Fowler-Nordheim tunneling, and conduction through trap levels.

The term "tunnel" will be used to refer to the term "tunnel" in which a carrier passes through at least part of the forbidden zone. ) Injecting carriers from a conductive opposing region into a semiconductor having a narrower bandgap than the thin film through a semiconductor thin film or an insulating thin film having a relatively thin film thickness and a wide bandgap, A semiconductor device that generates electron-hole pairs on the surface of a semiconductor region and performs light emission and light reception, accompanying amplification, switching, oscillation, voltage or current generation, negative resistance generation, etc., and its multiple functions. and related to its integrated circuits.

In a conventional p-n junction, the conditions for efficient carrier injection into one region are that both p-n regions forming the junction have good crystallinity, with few defects and Torasov level crabs, and that the impurity concentration is low. (The relationship tends to be limited and the impurity concentration in the region receiving implantation is an order of magnitude lower than that in the other region.) However, when designing a device, it is not always the best to consider the resistance and capacitance of each part. No design had been done. In addition, when direct injection was performed on the semiconductor surface, the carriers injected into the surface generated electron-hole pairs on the semiconductor surface and emitted light, and the injection of the injected carriers was promoted by incident light. Although useful functions were achieved with a small number of areas, it was difficult to realize a device that performed a new operation.

The present invention aims to eliminate these conventional drawbacks and provide a new device. To this end, the present invention uses injection of carriers through a thin film and generation of electron-hole pairs on the semiconductor surface by the injected carriers as the operating principle of the device. This thin film is thin enough to allow a large amount of carrier transport force due to its thin thickness (as expected from the bulk material, such as direct or indirect tunneling of carriers).
Moreover, if the forbidden band width is larger than that of the semiconductor conductor receiving carrier injection, even if the impurity concentration of the semiconductor receiving injection or the carrier concentration induced by the electric current from the opposing region is small, there is a gap between the opposing region and the semiconductor through the thin film. Is the conductivity type of carriers mainly transported between regions (hereinafter referred to as main carriers) the key to semiconductors? Can be set regardless of IJA concentration. In other words, by choosing a material relationship that has a lower thin film as seen from the semiconductor,! Injection from the inner region to the semiconductor region can be efficiently performed. In addition, even if you do not use such material relationship 1, select a thin film such that the carriers transported in this thin film are mainly single carriers, or have the opposite region have the polarity of the jaria that you want to transport in the thin film. The object of the present invention can be achieved by forming a conductive type semiconductor region.According to such a structure, the thin film and the opposing region do not necessarily have to be a single crystal with good crystallinity, but can also be polycrystalline. It may be amorphous.

Of course, the opposing region may be a metal electrode, and the thin film may be an insulating film such as S or 02.

Hereinafter, the present invention will be explained in detail through specific examples.

11 FIG. 1 shows an embodiment of the present invention, in which 100 is a semiconductor region to be implanted, 1 is a thin film of a material with a large forbidden band width, 1
0 is the opposing area. FIG. 1(b) shows an example of a band diagram of the device whose cross-sectional view is shown in (α), and shows a case where electrons are mainly transported between the facing region 10 and the semiconductor region. The following examples will also be explained assuming that the main carriers transported through the thin film are electrons, but if the main carriers are holes, the semiconductor receiving injection and the opposing region are semiconductors, the conductivity type of the opposing region will be explained. The pn relationship may be reversed by including .

In the cross-sectional structure shown in FIG. 1(a), although the thin film 1 allows a certain amount of current to flow, the potential of the opposing region 10 is set to a value larger than the voltage conversion value of the forbidden band width Eo of the semiconductor region 100 with respect to the semiconductor region 100.・If the carriers flowing are electrons, then on the negative side) and 1, if the thickness is i degrees that allows a reasonable current to flow without causing destruction, the band in Figure 1 (b) As shown in the diagram, when the opposing region 10 is biased above the conduction band of the semiconductor region 100 and above the voltage-equivalent value of the forbidden band width, the injected electrons are in a high energy state (in the e town and in the semiconductor region 1
Electron-hole pairs can be generated near the 00 surface.

The generated holes are collected on the surface of the semiconductor region 100, and when the semiconductor region 00 is n-type, the width of the surface depletion layer becomes smaller, which further promotes the injection of electrons from the opposing region 10, resulting in an on state. Become.

As a result, an electric IAw control type negative resistance as shown in FIG. 1(e) is obtained. In Figure 1(b), band diagram a shows the state before the generation of electron-hole pairs, and band diagram b shows that the generated holes are accumulated on the surface and that less voltage is required to flow the same current. Indicates that it is acceptable.

An example of experimental results for the specific example shown in FIG. 1 will be described next. Metal thin film, for example aluminum, thin film 1 as counter region 10
When using a top insulating film - for example, a clean 5ift film of around 30A, and a St single crystal containing 1011/C'11" phosphorus atoms as the semiconductor region, the negative polarity shown in No. 1-59 (c) Resistance characteristic break-o/(Yo voltage V, -4V to -5V, holding voltage vH -3.1 to 43.2V,
The holding current density (-holding current II/de cuimo area) was about 2 μA/.l. Furthermore, when the opposing region of this experimental sample is biased between -3.2 V and -14 V with respect to the semiconductor region, and light from a light emitting diode or about 500 mW tungsten lamp is incident in a spiral pattern, the state transitions from the OFF state to the ON state. do. This state continued even after the light was removed unless the bias voltage was changed to the lower voltage side than the holding voltage vh. This experimental example demonstrates that according to the present invention, it is possible to realize an optical switch with a simple structure.

The semiconductor region 100 is made of GaAs, Gap, Inp,
GILXAII-LAS.

In the case of a luminescent material such as GaAsxP+-x, when high-energy carriers (e) lose energy, or when electron-hole pairs are generated, light is obtained when the holes recombine on the surface and disappear. be able to.

Even a non-luminescent substance such as Fi-1 can be used as the operating principle of various electronic devices, in which electron-hole pairs are generated by high-energy carriers.

- Figure 2 shows one of the specific examples, in which holes generated by high-energy carriers injected from the opposing region 10 are
A p-type semiconductor region 101 provided in contact with the n-type semiconductor region 100 and within the reachable distance due to hole diffusion or drift.
When collected at B, a positive potential can be extracted from the region 101B even though a negative bias is applied to the opposing region 10. In other words, in addition to receiving and emitting light, it can also be used as a power source with reversed polarity having the characteristics shown in FIG. This is convenient for obtaining biases with different polarities in integrated circuits and the like. In FIG. 2, the region 101B generally only needs to have a rectifying junction with the semiconductor region 100, and can be made of a different material. Figure 4 shows a concrete example of this application. As shown in the figure, on the high impurity concentration n shadow region 100b, 10' to 1016
np! of a multi-collector with a p-type base and a p-type gate transistor in the substrate surface forming an n-shaded region 100a of the order of . Although one bipolar transistor can be fabricated at the same time, a negative power source and a positive power source are required to operate one bipolar transistor at the same time on the same substrate. However, if the specific example of the present invention shown in Figure 1 is further applied, the required external power source can be reduced to Category 18. In the cross-sectional view (α), regions 110 and 111
indicate the source and train slopes of the insulated gate transistor, respectively, 112 indicates the insulated gate, and 113 indicates the gate insulating film. Region 10Fi is the opposing region, 1 is the thin film, and 10IB is the region that collects minority carriers generated on the surface of the value range 100α by high energy energy carriers that have passed through the thin film 1 with a ton or the like. is provided within the reach of minority carriers from the junction surface of. , region 1nIB is of the opposite conductivity type to region 100a, and is p-type in this example. Area 104A,! :
104B is a region 101B formed in the region 101B.
, are regions of inverse quadruplicity, forming a multi-collector of npn transistors. The base of the above-mentioned npn) transistor is common to the carrier collection region 101B described above, and the emitter is the substrate 1()0α.

It is formed in 1 qob. In the figure, the portion indicated by CT+1 is an amplifier circuit or a logic circuit for the output of an NPN transistor which operates with a negative bias applied to the opposing region 10, as shown in the equivalent circuit (CT+) of FIG.

On the other hand, as shown in the equivalent circuit of FIG. 13(b), the portions marked with gloss are p-channel insulated gate transistors, which can be used as circuit elements that operate with a negative bias. Therefore, by using the present invention, an integrated circuit that conventionally required two bipolar power supplies can be operated with a single power supply. In addition, referring to the equivalent circuit in figure (b), the symbol Fi<a) shown on each terminal indicates a terminal drawn out from the electrode or region in figure (b). Furthermore, in Fig. 4, the region B, which collects holes generated by high-energy electrons, and the two regions of the Bibo 2 transistor are common.
A high-density integrated circuit including the photoelectric device of the present invention is realized.

Channel region 1 as shown by the dotted line in Figure 4 (α)
If you create 05A and 105B, area 101B will become a haiku area (1
00a+100b) as the source region, 104A, 10
It also functions as a gate of a field effect transistor with 4B as the drain, and can be made in common with the hole collection region. In this case, the region 101B is not a p-type semiconductor but also a heavy semiconductor.
Rectifying junction area 1001! (a metal or a semiconductor forming a heterojunction with 100a) may be used.

In order to operate this integrated circuit as a direct-coupled logic circuit, the gate region 101B and the source range (100a +
A channel impurity concentration 7-dimensional relationship is selected such that the channel region is depleted.

FIG. 5 shows two other embodiments of the present invention, in which the semiconductor range 100 in FIG.
Consisting of 1. The thin ill is provided in contact with the region 101. The band diagram in the case where all the 5th rears in the four cases on the lfr surface and surface side are electrons is shown in (b). Via 1 is applied between the region 102 and the opposing region 341o, and the main carriers from the opposing region 10 are injected into the semiconductor region 101 through the thin film 1-1 in the direction L; When the difference between the band edges of region 100 and the region 1°01 becomes larger than the forbidden band width of region 101, electrons and
Hole pairs are generated, and the region 101, which was in a reverse bias state with respect to the region 102, is charged by the carrier having the opposite polarity to the main carrier, as shown in the band diagram (b). Close to zero bias. As a result, the electric field in the thin film 1 is strengthened, so that more and more high-energy carriers are injected. At this time, thin [1 and area 102
If the distance between the regions 101 and 1 is within the reach of the main carriers of the thin M1 due to diffusion or drift, the main carriers injected into the region 0] (minority carriers in the region 101-) ) reaches 102, and the conclusion is,
Once electrons and holes are generated in the structure shown in FIG. 5, a large current flows between the opposing regions 10 and 102.

Therefore, if the external terminal does not extend from the region 101, the light 1! exhibits a current-controlled negative resistance or switch characteristic that can be controlled by optical input! The element can be obtained and the region 101
If the terminal 101E is outputted from the terminal 101E, it can be used as a control terminal for the above-mentioned element, and can also be used as a light-emitting or photo) transistors can be obtained. In the above description, the region 102 may be made of a different material as long as it has a rectifying junction with the semiconductor region 101. The above explanation of the operating principle can also be applied to the device shown in FIG. 4 when high energy carriers are injected from the opposing region 10. In this case, the region 101B is also the control terminal for switching characteristics, and the base of the light emitting or phototransistor. The base connection area, which also serves as the connection terminal, exhibits negative input impedance, and? The i-directed region 10 serves as an emitter, and the semiconductor region 102 serves as a collector.

Next, an example of an integrated circuit using the photoelectric element shown in FIG. 5 will be described.

FIG. 6 Fi is a specific example when the device shown in FIG. 5 is used in a memory cell.
Fi shows its operating waveform. In the figure, a region 1102 is used as a semiconductor substrate, and a region 101 of the opposite conductivity type to the region 1102 is a common region with the drain of the insulated gate electric field transistor 11. Opposing region 10 is connected to resistive element R via wiring 10E, and the other end of R is connected to power supply voltage vbtl. Insulated Gate Field Effect Transistor (IGFET>) The insulated gate 112 is connected to the X-ray, and the source region 110 of the IGFET is connected to the Y-line to be selected as the XY address of the memory array on the matrix 7. The operation of this cell will be explained below. First, it is assumed that the IGFET is a p-channel for simplicity. In this case, the thin film 1 is made of thin SiOz (approximately 30A to 50A) that can be tunneled, and if it is a full wall, it is made of a material doped with impurities such as tungsten.
10 may be a metal thin film, or it will be more effective if it is an n-type semiconductor with a wide bandgap such as 5 hoz. First, if the potential of the region 101 is closer to the voltage source than the substrate 102, it is set to '1'! ,! The case where the voltage is on the substrate voltage side is set as 10'.

For 'O' writing, first apply a suitable negative voltage to the gate of the IGFET, and when a voltage closer to the substrate is applied to the source, the region 101 also rises to a voltage close to the voltage of the source. In the element of the great invention that is composed of the region 10, the thin film 1, the region 101, and the region 102, a large voltage is applied between the opposing region 41 and the region 101, so that the opposing region 1
Electrons due to high energy main carriers injected from 0
Since the generation of hole pairs occurs and thereafter high energy carriers are supplied from vDD through R, the state Fi persists even if the gate voltage is returned to the potential that would turn it off. Region 101 is held at a potential near substrate 102 .

In the case of 11' writing, if a potential close to vDD is applied to the gate and source, the region 101 will also reach the same potential, and even if high-energy carriers have been injected before writing, traces will be created. Afterwards, even if the potential of the gate of the IGFET is returned to the OFF state, the region 101 is maintained at a potential close to vDゎ.The leakage current due to the reverse bias of the C regions 101 and 102 passes through R and from vt, t. thin film 1
Since the system is supplied with a single ledger, there is no need for a french operation like in the conventional Dynaminokume 1.

A large amount of information can be written into the incident light, and if a play configuration is used, static storage and random access reading of the optical image is also possible. If the semiconductor region is made of a luminescent material, it is also possible to display stored information by luminescence. On the other hand, since the wafer occupancy area is approximately one transistor, a high-density static memory can be obtained.

In order to reduce the power during standby, R should be an element with high resistance (or an element that exhibits constant current characteristics) with equal constraints.
Since a micro current element (small current element) is normally used, a relatively large current is read out in high-speed readout, resulting in so-called destructive readout, resulting in a long cycle time. In order to avoid this, in place of the resistive element R, as shown in FIG.
It is conceivable to insert them in series between the rows. The resistive element R can be integrated in a small area using polycrystalline S, thin film, etc. constructed on an erodible film, but in this case, the unit cell requires the area occupied by two transistors. By setting the gate of the connected IGFET QR to 1 in the direction of lower resistance during reading, it is possible to pretend that non-destructive reading is possible and achieve high-speed operation.

In addition, in FIG. 6, if a non-ipolar transistor is formed with the region 101 as the collector, a memory cell with the non-ipolar transistor as a selection element can be realized. Alternatively, the power can be shared with the source and the collector of a bipolar transistor to provide a high-density memory cell capable of displaying information content by optical storage or light emission.
I can do something.

Furthermore, as shown in FIG. 8, the opposing area 10.71VIP'1
Semiconductor region] A region 101D having a rectifying junction with the semiconductor region and one or many electrodes that are close to each other but not in contact with each other is provided in close proximity to the element consisting of CC.
D operation, series MDS) Functional devices can be realized by transistor operation. The configuration shown in FIG. 8 performs the following functions, for example. First, the insulated gate 121,1
22...] When 27 is a continuous L17t one gate, area 101D t: Stores an optical image with the convolution readout line and insulated gate as an address selection line, or displays stored information two-dimensionally by emitting light. operates as a unit cell in a memory array. Second is insulation goo) 121, 122
... 127 is driven with appropriately phase-shifted pulses to cause CCD operation, and a light emission signal is sent to the device portion of the present invention consisting of the facing region 10, the thin film 1, and the semiconductor region 100, and the light is emitted without any reflex action. can be memorized. In addition, a sieve can be formed that transfers the light to the received light signal area 101D and reads out the meeting information. Third, a signal charge is sent to the device part of the present invention by the CCD operation, and when a predetermined amount of charge is accumulated, the device of the present invention turns on, that is, emits light. It is possible to realize various useful functions such as counting the number of signal charges, driving), and dividing the frequency of pulses.

In the above description of the specific example, electrons were used as the main carriers, but in the case of holes, in order to efficiently extract light from the opposing region 10 side in the case of four devices in each semiconductor region, and to irradiate it. The opposing region 10 is at least the semiconductor region 1
In the case of a semiconductor with a forbidden band width larger than 000, or a thin film thickness of several hundred times or less in the case of a metal, or a structure with a large number of slits even if it is an opaque material, it has a light transmittance. It needs to be structured. However, especially in the case of a light-receiving device (chair), it has been confirmed that it operates satisfactorily even with incident light from the periphery of the opaque opposing region.

According to the structure of the present invention, it is possible to realize a photoelectric device with a good power by using a wider range of characteristics than conventional ones in designing not only the opposing region but also the crystallinity and impurity concentration of the semiconductor region, which is one of the structural requirements. can. In particular, light [functions can be realized at the same time as the New Autumn circuit].

[Brief explanation of drawings]

1 to 8 show embodiments of the present invention. In the figure, 1 is a thin film, 10 is an opposing region, and 100 is a semiconductor region. jifu 1 (', 2) 11th twist 2 Figure ioo Fortune 7 scale 3 = n "1 Half 4 Figure (CT,) Culture 5 Figure 〉shi Otsu Figure J, =< - 17'

Claims (1)

[Scope of Claims] 1) Consists of at least a semiconductor region, a counter region facing the semiconductor region, and a thin film of a material having a wider forbidden band width than the semiconductor region, and the thickness of the thin film is equal to that of the counter region and the semiconductor region. Inject carriers into the semiconductor region from the opposing region to the semiconductor region with an energy greater than the energy gap of the semiconductor region, so that carrier transport between the regions is carried out through transport that passes at least partially within the forbidden zone of the thin film. A photoelectric element in which carriers are injected from the opposing region into the semiconductor region using bias means for generating electron-hole pairs on the surface of the semiconductor region, thereby emitting or receiving light. 2) In the photoelectric device according to claim 1), the thin film has a barrier height lower than the main carrier when viewed from the opposing region, and a barrier height of the thin film when viewed from the semiconductor region. A photoelectric element made of a material that has a high polarity for carriers of opposite polarity to the main carrier. 3) The photoelectric device according to claim 1), wherein the carriers transported within the thin film are mainly of single polarity. 4) The photoelectric device according to claim 1, wherein the opposing region is a semiconductor region having a conductivity type having the same polarity as the polarity of the main carrier of the thin film. 5) In the photoelectric device according to claim 1), the semiconductor region has a second region having a rectifying junction with the semiconductor region within a range that carriers can reach from the junction surface with the thin film. A photoelectric element consisting of 6) The photoelectric device according to claim 5, wherein the opposing region is an emitter, the semiconductor region is a base, and the second region is a collector, and the photoelectric device operates as a bipolar transistor. 7) In the photoelectric element according to claim 5), an inversion layer or a depletion layer is formed on the surface of the semiconductor region opposite to the opposing region, the opposing region is an emitter, and the inversion layer or depletion layer is a base. the semiconductor region as a collector;
A photoelectric device in which the second region is used as a base connection region and operates as a bipolar transistor. 8) In the photoelectric device according to claim 5, the second region generates a voltage with the opposite sign to the voltage applied to the opposing region with respect to the semiconductor region, or generates a voltage applied to the semiconductor region from the opposing region. A photoelectric element for power supply that allows current to flow in the opposite direction to the incoming current. 9) A switching photoelectric device according to claim 5, in which the semiconductor region is used as a region for controlling switching characteristics between the opposing region and the second region. 10) In the photoelectric device according to claim 5),
A switching photoelectric element using the second region as a region for controlling switching characteristics between the opposing region and the semiconductor region. 11) In the photoelectric device according to claim 1),
an insulated gate that is insulated and proximate to the opposing region and is provided on the semiconductor region via an insulating film; A semiconductor integrated circuit comprising a third region having a junction. 12) The semiconductor integrated circuit according to claim 11, wherein the insulated gate is composed of a plurality of insulated gate portions whose adjacent portions are insulated from each other.