CN210272383U - Graphene-metal heterojunction photoelectric detector with concave array - Google Patents

Abstract

The utility model discloses a can increase the sensitive surface, increase the absorption that graphite alkene was set a camera, avoid the transfer process to the graphite alkene concave surface array's that causes destruction graphite alkene-metal heterojunction photoelectric detector. The graphene-metal heterojunction photoelectric detector with the concave array comprises a substrate; an insulating layer, a growth layer and a graphene layer are sequentially arranged on the substrate from bottom to top; the substrate is provided with downward concave grooves distributed in an array manner; a first convex surface matched with the groove is arranged on the insulating layer; a second convex surface is arranged on the growth layer; a third convex surface is arranged on the graphene layer; an anti-reflection layer is arranged on the inner wall of the inner groove of the third convex surface of the graphene layer; and the two sides of the inner groove of the third convex surface on the graphene layer are respectively provided with a high work function electrode and a low work function electrode of wave-shaped interdigital. The graphene-metal heterojunction photoelectric detector adopting the concave array has the characteristics of small volume, high integration level, wide identification range and the like.

Description

Graphene-metal heterojunction photoelectric detector with concave array

Technical Field

The utility model belongs to the technical field of communication and sensor and specifically relates to a graphite alkene-metal heterojunction photoelectric detector of concave surface array.

Background

It is well known that: the principle of the photodetector is that radiation causes a change in the conductivity of the irradiated material. The photoelectric detector has wide application in various fields of military and national economy. The infrared radiation sensor is mainly used for ray measurement and detection, industrial automatic control, photometric measurement and the like in visible light or near infrared wave bands; the infrared band is mainly used for missile guidance, infrared thermal imaging, infrared remote sensing and the like.

The mainstream structure of the existing graphene photoelectric detector is a planar structure, so that the light receiving surface is small, the absorption of graphene to light is small, and the prepared graphene is transferred to a detector substrate by a common graphene photoelectric detector, so that the graphene is easily damaged in the transfer process.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that a graphite alkene-metal heterojunction photoelectric detector of concave surface array that can increase the sensitive surface, increase the absorption that graphite alkene set a light, avoid the transfer process to the destruction that graphite alkene caused is provided.

The utility model provides a technical scheme that its technical problem adopted is: the graphene-metal heterojunction photoelectric detector with the concave array comprises a substrate; an insulating layer, a growth layer and a graphene layer are sequentially arranged on the substrate from bottom to top;

one or an array of downward concave grooves is arranged on the substrate; a first convex surface which is convex downwards and matched with the groove is arranged on the insulating layer; the grooves correspond to the first convex surfaces one to one;

a second convex surface which is convex downwards and is matched with the inner groove of the first convex surface is arranged on the growth layer; the inner grooves of the first convex surfaces correspond to the second convex surfaces one to one;

a third convex surface which is convex downwards and is matched with the inner groove of the second convex surface is arranged on the graphene layer; the inner grooves of the second convex surfaces correspond to the third convex surfaces one by one;

an anti-reflection layer is arranged on the inner wall of the inner groove of the third convex surface of the graphene layer; and the two sides of the inner groove of the third convex surface on the graphene layer are respectively provided with a high work function electrode and a low work function electrode of wave-shaped interdigital.

Specifically, the substrate is provided with downward concave grooves distributed in a 3X3 array.

Further, the insulating layer is a silicon dioxide film.

Preferably, the groove is a hemispherical groove.

Preferably, the growth layer is formed by depositing Cu or Au or Ag or Mo or Gr at the thickness of 30-70 nm and depositing Ni at the thickness of 30-70 nm; or a layer of 30-70 nm aluminum oxide directly deposited on the growth layer.

Further, the graphene layer is a graphene film directly grown on the growth layer by a CVD method; and the number of layers of the graphene film is 1-10.

Preferably, the anti-reflection layer is a silicon dioxide film with the thickness of 30-100 nanometers.

Specifically, the low work function electrode is made of titanium (Ti), platinum (Pt), manganese (Mn), lithium (Li), or aluminum (Al); the thickness is 50-100 nm.

Specifically, the high work function electrode is made of gold (Au), silver (Ag), nickel (Ni) or palladium (Pd), and the thickness of the high work function electrode is 50-100 nanometers.

The utility model has the advantages that: concave surface array's graphite alkene-metal heterojunction photoelectric detector, owing to adopted concave surface structure, the light-absorbing surface can increase under the same surface area to concave surface structure can make the graphite alkene surface of light in the concave surface carry out multiple reflection, increases the absorption that graphite alkene set a light, so relatively speaking, the responsivity that the detector set a light can be than higher. Because the growth layer is deposited on the substrate and the graphene film is directly deposited on the surface of the growth layer, the damage of the graphene film caused by the transfer of the graphene is avoided, so that the electrical property of the graphene is relatively excellent, and the sensitivity of the photoelectric detector can be increased; the electrical property of the graphene is relatively excellent, and the preparation process is simple, mature and reliable.

Therefore, concave surface array's graphite alkene-metal heterojunction photoelectric detector, can carry out quick detection to the light signal of different wavelength and light intensity under normal atmospheric temperature, have characteristics such as small, the integrated level is high, the identification range is wide. In addition, the preparation process of the device is relatively simple, is compatible with the existing semiconductor preparation process, and can realize mass production. Has better application prospect in the fields of optical detection, optical communication and the like.

Drawings

Fig. 1 is an exploded schematic view of a graphene-metal heterojunction photodetector with a concave array in an embodiment of the present invention;

fig. 2 is a perspective view of a graphene-metal heterojunction photodetector with a concave array in an embodiment of the present invention;

fig. 3 is a top view of a graphene-metal heterojunction photodetector with an array of concave surfaces in an embodiment of the present invention;

FIG. 4 is a sectional view A-A of FIG. 3;

fig. 5 is a cross-sectional view of a single groove of a concave array of graphene-metal heterojunction photodetectors in an embodiment of the invention;

the following are marked in the figure: 1-substrate, 2-insulating layer, 3-growth layer, 4-graphene layer, 5-antireflection layer, 6-high work function electrode and 7-low work function electrode.

Detailed Description

The present invention will be further explained with reference to the drawings and examples.

As shown in fig. 1 to 4, the graphene-metal heterojunction photodetector with a concave array according to the present invention includes a substrate 1; the substrate 1 is sequentially provided with an insulating layer 2, a growth layer 3 and a graphene layer 4 from bottom to top;

the substrate 1 is provided with one or a plurality of downward concave grooves 11 distributed in an array; a first convex surface 21 which protrudes downwards and is matched with the groove 11 is arranged on the insulating layer 2; the grooves 11 correspond to the first convex surfaces 21 one by one;

a second convex surface 31 which protrudes downwards and is matched with the inner groove of the first convex surface 21 is arranged on the growth layer 3; the inner grooves of the first convex surfaces 21 correspond to the second convex surfaces 31 one by one;

a third convex surface 41 which is convex downwards and matched with the inner groove of the second convex surface 31 is arranged on the graphene layer 4; the inner grooves of the second convex surfaces 31 correspond to the third convex surfaces 41 one by one;

an anti-reflection layer 5 is arranged on the inner wall of the inner groove of the third convex surface 41 of the graphene layer 4; and the two sides of the groove in the third convex surface 41 on the graphene layer 4 are respectively provided with a high work function electrode 6 and a low work function electrode 7 which are formed by wavy interdigital.

Specifically, the insulating layer 2 is a silicon dioxide film. Specifically, the growth layer is formed by depositing Cu or Au or Ag or Mo or Gr at the thickness of 30-70 nm and then depositing Ni at the thickness of 30-70 nm; or a layer of 30-70 nm aluminum oxide directly deposited on the growth layer.

Specifically, the anti-reflection layer 5 is a silicon dioxide film with the thickness of 30-100 nanometers.

Specifically, the low work function electrode 7 is made of titanium (Ti), platinum (Pt), manganese (Mn), lithium (Li), or aluminum (Al); the thickness is 50-100 nm.

Specifically, the high work function electrode 6 is made of gold (Au), silver (Ag), nickel (Ni) or palladium (Pd) and has a thickness of 50 to 100 nm.

To increase the absorption of light by the graphene layer 4, the grooves 11 are further hemispherical grooves.

In order to avoid the transfer of the graphene, the electrical property of the graphene is improved, so that the sensitivity of photoelectric detection is improved. Further, the graphene layer 4 is a graphene film directly grown by a CVD method; and the number of layers of the graphene film is 1-10.

Concave surface array's graphite alkene-metal heterojunction photoelectric detector, graphite alkene and metal electrode contact can form the contact heterojunction, the metal and the graphite alkene contact of two kinds of different work functions form two different heterojunctions, form the built-in electric field between the heterojunction. When light irradiates the surface of graphene, electrons in the graphene absorb photon energy so as to generate transition. Therefore, the non-equilibrium photon-generated carriers such as electron-hole pairs are formed in the graphene film, and the photon-generated carriers directionally move under the drive of an internal electric field to form photocurrent, so that the aim of detecting light is fulfilled.

Present graphite alkene photoelectric detector's mainstream structure is planar structure, and concave surface array's graphite alkene-metal heterojunction photoelectric detector, adopted concave surface structure, increased the sensitive surface, concave surface structure can make the graphite alkene surface of light in the concave surface carry out multiple reflection, increases the absorption that graphite alkene was set a camera to general graphite alkene photoelectric detector all shifts the graphite alkene that has prepared to the detector basement, and the utility model discloses direct growth layer surface preparation graphite alkene film at the detector basement has avoided the destruction that the transfer process led to the fact graphite alkene.

Therefore, the graphene-metal heterojunction photoelectric detector of the concave array has the following beneficial effects:

1) the graphene covering the surface of the concave structure is used as a sensitive material, and the concave structure can enable light to be reflected for multiple times on the surface of the graphene in the concave surface, so that the absorption of the graphene to the light is increased, and the sensitivity of the photoelectric detector is improved.

2) The growth layer is deposited on the substrate, so that the graphene film can be conveniently and directly deposited on the detector by adopting a CVD (chemical vapor deposition) method, the transfer of the graphene is avoided, the electrical property of the graphene is improved, and the sensitivity of photoelectric detection is improved.

3) The preparation process is compatible with the existing semiconductor device preparation process, the integrated design and preparation of the detector are extremely easy to realize, and the practicability of the detector is greatly improved.

4) The concave array structure is adopted, the light receiving surface of the detector is increased, the active area of graphene can be fully increased due to the contact of the asymmetric wave-shaped interdigital electrode and the graphene, and the sensitivity of the detector is further increased conveniently.

Examples

As shown in fig. 1 to 4, the graphene-metal heterojunction photodetector with a concave array comprises a substrate 1; the substrate 1 is sequentially provided with an insulating layer 2, a growth layer 3 and a graphene layer 4 from bottom to top;

a groove 11 which is concave downwards is arranged on the substrate 1; a first convex surface 21 which protrudes downwards and is matched with the groove 11 is arranged on the insulating layer 2;

a second convex surface 31 which protrudes downwards and is matched with the inner groove of the first convex surface 21 is arranged on the growth layer 3; a third convex surface 41 which is convex downwards and matched with the inner groove of the second convex surface 31 is arranged on the graphene layer 4;

an anti-reflection layer 5 is arranged on the inner wall of the inner groove of the third convex surface 41 of the graphene layer 4; and 6 high work function electrodes 6 and low work function electrodes 7 are respectively arranged on two sides of the groove 11 on the substrate 1.

The insulating layer 2 is a silicon dioxide film. The groove 11 is a hemispherical groove. The growth layer is formed by depositing Cu or Au or Ag or Mo or Gr at the thickness of 30-70 nm and then depositing Ni at the thickness of 30-70 nm; or a layer of 30-70 nm aluminum oxide directly deposited on the growth layer.

The graphene layer 4 is a graphene film directly grown by a CVD method; and the number of layers of the graphene film is 1-10. The anti-reflection layer 5 is a silicon dioxide film with the thickness of 30-100 nanometers. The low work function electrode 7 is made of titanium (Ti), platinum (Pt), manganese (Mn), lithium (Li) or aluminum (Al); the thickness is 50-100 nm. The high work function electrode 6 is made of gold (Au), silver (Ag), nickel (Ni) or palladium (Pd), and the thickness is 50-100 nanometers.

The specific preparation process adopts the following processes:

1) adopting a photoetching technology to form a circular hole pattern with the diameter of 5-10 microns in a 3X3 array distribution on the surface of the substrate 1;

2) a concave structure is processed on the surface of the silicon substrate 1 by adopting plasma etching (ICP) or hydrofluoric acid, and then the photoresist on the surface is removed, wherein the depth of the concave is about 1 micron.

3) And depositing a silicon dioxide film as an insulating layer 2 on the silicon wafer with the processed concave surface by adopting a magnetron sputtering process, wherein the thickness of the silicon dioxide is about 50-100 nanometers.

4) Depositing a growth layer 3 (an alloy of one of Cu, Au, Ag, Mo and Gr and Ni) on the silicon dioxide insulating layer by adopting a magnetron sputtering process, firstly depositing Cu or Au or Ag or Mo or Gr with the thickness of about 50 nanometers, and then depositing Ni with the thickness of about 50 nanometers; or a layer of 30-70 nm aluminum oxide directly deposited on the growth layer.

5) And (4) directly growing a graphene layer 4 on the surface of the growth layer 3 deposited in the step (4) by adopting a CVD method.

6) And (3) depositing asymmetric active metal low work function electrodes 7 at two ends of the graphene by adopting a photoetching technology and a magnetron sputtering process: titanium (Ti), platinum (Pt), manganese (Mn), lithium (Li), aluminum (Al), and high work function electrode 6: gold (Au), silver (Ag), nickel (Ni) and palladium (Pd), wherein the thickness of each electrode is 50-100 nanometers, and then the photoresist on the surface is removed.

7) And depositing a layer of antireflection film 5 (silicon dioxide) on the concave surface of the graphene by adopting a photoetching technology and a magnetron sputtering process, wherein the thickness of the silicon dioxide is 30-100 nanometers, and then removing the photoresist on the surface.

Specifically, the photolithography process (negative resist RPN-1150) is performed by the following steps:

1. gluing;

spin-coating a layer of photoresist on the surface of a sample wafer by using a photoresist homogenizer, wherein the rotating speed of the photoresist homogenizer is set as follows: firstly rotating at low speed (1000 rpm) for 10s, and then rotating at high speed (3000 rpm) for 40 +/-2 s; the thickness of the photoresist after spin coating is 2.5 +/-0.05 m;

2. pre-baking;

before gluing, turning on a hot plate power switch, and setting the heating temperature to be 90 +/-2 ℃; after the temperature is stable, placing the sample wafer coated with the photoresist on a hot plate for baking for 90 +/-1 s;

3. exposing;

turning on a power switch of a photoetching machine, turning on a mercury lamp for preheating for more than 20 minutes, mounting a mask plate on a mask clamp, placing a dried sample wafer on a sample tray, moving the sample carrying tray to align the sample wafer with a pattern on the mask plate, setting the exposure time to be 7.5 +/-0.5 s after the plate alignment is completed, and starting exposure;

4. postbaking;

setting the temperature of a hot plate to be 110 +/-2 ℃, after the temperature is stable, placing the exposed sample wafer on the hot plate, baking for 60 +/-10 seconds, and quickly taking down the sample wafer from the hot plate;

5. developing;

filling a proper amount of developing solution with the model of RZX-3038 in a clean culture dish, putting the sample wafer subjected to post-drying treatment into the developing solution for developing for 50 +/-2 seconds, then washing the sample wafer for multiple times by using deionized water, and finally drying the sample wafer by using an N2 gun;

6. ultraviolet ozone cleaning treatment;

placing the developed sample wafer into a chamber of an ultraviolet ozone cleaning machine (BZS250GF-TC), turning on a power switch, setting the photoresist removing time to be 3-5 minutes, turning on an ultraviolet lamp switch, and beginning to remove residual photoresist in a pattern area;

7. hardening the film;

placing the sample wafer subjected to ultraviolet ozone cleaning treatment on a hot plate at the temperature of 110 +/-2 ℃ for baking; the baking time is 5-15 minutes; after baking was complete, the hotplate power was turned off and samples taken.

Specifically, the magnetron sputtering is carried out by adopting the following process:

magnetron sputtering is one type of Physical Vapor Deposition (PVD). The general sputtering method can be used for preparing multi-materials such as metal, semiconductor, insulator and the like, and has the advantages of simple equipment, easy control, large film coating area, strong adhesive force and the like. The utility model mainly adopts the method to sputter a silicon dioxide insulating layer, a growth layer, an electrode and a silicon dioxide antireflection film.

The experimental procedure was as follows:

1. starting up;

opening a power switch of the air compressor and an air path valve of the air compressor; turning on a power switch of the water chiller; opening a valve of the protective gas cylinder; pressing a 'total power supply starting' button of a control panel, and pressing 'total power starting'; pressing a radio frequency power supply starting button or a direct current power supply starting button; opening control software to ensure that the vacuum gauge is closed, clicking an inflation valve to inflate the chamber, and waiting for the inflation to be completed;

2. target loading and lofting;

pressing the 'up' button for a long time until the indicator light next to the up button turns green; selecting a required target position in a baffle control panel, opening a baffle and replacing the target; after the target material is replaced, selecting a sputtering mode: the method comprises the following steps of (1) sputtering by a straight target, manually adjusting a target position, and manually adjusting a baffle plate to ensure that the baffle plate blocks the sputtering target position in a state that the baffle plate is closed; placing a sample wafer according to the selected sputtering mode; pressing down button for a long time until the indicator lamp beside the button turns green to ensure that the top cover is covered and the chamber observation window door is closed;

3. vacuumizing;

clicking a mechanical pump and a front valve on a control panel to wait for dozens of seconds, then clicking a molecular pump, closing the front valve and opening a pre-pumping valve after the molecular pump starts to rotate. When the pressure of the equal cavity chamber is reduced to be below 3.5Pa, the vacuum gauge is opened, the pre-pumping valve is closed, the backing valve is opened, and the gate valve is opened; when the pressure of the equal cavity is reduced to be below 5Pa, the vacuum gauge is closed in a single click mode, and then required gas is introduced into the cavity through the single click of Vpg1, Vpg2 and Vpg 3;

4. sputtering;

in the operating pressure control panel, the ignition pressure: 5 +/-0.5 Pa, clicking to determine, inputting a starting numerical value after the pressure reaches a set value, clicking to turn on a button, and observing whether plasma is generated at a target position; after plasma is generated, further adjusting the background pressure of sputtering to be 0.8 +/-0.1 Pa; after the plasma is stabilized, pre-sputtering for about 5 minutes, then opening a baffle plate for sputtering, recording the time, and after 30 +/-3 minutes, closing the baffle plate of the sputtering target and stopping sputtering;

5. sampling;

clicking an 'off' button on a power panel to turn off the power, inputting a gas flow value of 0, and then turning off 'Vpg'; closing the gate valve, clicking the air release valve to inflate the chamber; and taking out the sample wafer after the inflation is finished.

Specifically, the preparation of graphene by the CVD method is carried out by adopting the following processes:

CVD is a short term for Chemical Vapor Deposition and refers to a gas phase reaction at a high temperature, for example, a thermal decomposition of a metal halide, an organic metal, a hydrocarbon, or the like, a hydrogen reduction, or a method of causing a mixed gas thereof to undergo a Chemical reaction at a high temperature to precipitate an inorganic material such as a metal, an oxide, a carbide, or the like. The utility model discloses a growing layer surface growth graphite alkene, with one deck Ni deposit to Mo or Cu or Au or Ag or Gr on, perhaps directly adopt the aluminium oxide of deposit one deck 30 to 70 nanometers as the growth layer. Then preparing graphene by adopting a low-pressure CVD method, and finally directly generating a few-layer graphene film on the surface of the growth layer. The experimental procedure was as follows:

1. preprocessing a growth layer; sequentially wiping the surface of the growth layer with acetone and absolute ethyl alcohol, then placing the sample wafer in a culture dish filled with deionized water, carrying out ultrasonic treatment for 3-5 min, and finally blowing the sample wafer by using a nitrogen gun.

2. Place the coupon into a reaction chamber (2 "quartz tube); the treated sample wafer was placed on a quartz boat, the quartz boat was fed from one end of the quartz tube to a suitable position (heating temperature zone of tube furnace) by means of a glass rod, and then the quartz tube was sealed.

3. Setting growth parameters; mainly sets the heating temperature and the gas flow of the two-temperature-zone tube furnace. The temperature parameters mainly comprise temperature rise time, temperature and holding time in an annealing stage and temperature and holding time in a growth stage; the gas parameters mainly include the flow rates of hydrogen, argon and methane.

4. Vacuumizing; and continuously vacuumizing for 5-10 min by using a mechanical pump, and entering the next operation when the pressure of the reaction chamber is lower than 0.1 Pa.

5. Heating and annealing; and introducing a mixed gas of a protective gas and argon and hydrogen with the flow of 100 sccm. And opening a heating switch of the tube furnace, heating to 900 ℃, keeping the constant temperature for annealing, wherein the annealing time is 30 min.

6. Growing graphene; after the annealing is finished, changing the mixed gas of argon and hydrogen into hydrogen with the flow of 100 sccm; and (3) heating the tubular furnace to 1000 ℃, keeping the temperature constant, then introducing methane with the flow of 5-30 sccm, and starting to grow graphene. The growth time is 15-60 min.

7. Cooling and sampling; after the graphene grows, closing methane, withdrawing the heating program to stop heating, then opening the top cover of the tubular furnace to rapidly cool, and keeping introducing hydrogen in the cooling process. And when the temperature of the tubular furnace chamber is reduced to below 50 ℃, closing hydrogen, stopping vacuumizing, and finally breaking vacuum to take out the sample wafer.

Specifically, the plasma etching (ICP) employs the following process:

ICP is an abbreviation for plasma etching, which is one of etching processes for fabricating semiconductor integrated circuits. When removing the unnecessary protective film on the integrated circuit board, a reactive ion etching method is called as a reactive ion etching method, in which the chemical bond of the protective film material is cut by an ion beam of a reactive gas to generate a low molecular material and volatilize or dissociate the low molecular material from the board surface. The utility model adopts the method to etch silicon, so that a concave surface is formed on the surface of the silicon, and the illuminated surface is enlarged. The specific experimental procedure is as follows:

(1) preparing;

before the experiment, whether all parts of the whole machine are in good states or not is checked, and after no problem exists, the cooling water tank is opened firstly, then a main switch of a power supply at the lower part of the electric control cabinet is switched on, and the experiment operation is prepared.

(2) Loading a sample wafer;

and pressing a VINC switch of an air charging valve of the etching chamber of the central control system, filling air into the etching chamber, after the air charging is finished for 4 minutes, turning on a lifting permission indicating lamp, pressing a lifting button, lifting an upper cover, putting a target sample wafer on an electrode, pressing a lifting button, falling the upper cover, covering the upper cover well, and closing the VINC valve.

(3) Vacuumizing;

and (3) starting a power supply of a vacuum gauge, starting the RPC (remote position control) of the mechanical pump, pre-pumping the front stage of the molecular pump, starting the molecular pump (determining whether cooling water of the molecular pump is introduced or not) after the mechanical pump runs for about 2 minutes, waiting for the normal running of the molecular pump, opening the pre-pumping valve VPRC, opening the gate valve after the vacuum degree reaches 2Pa, and pumping the vacuum chamber to high vacuum.

(4) And turning on two radio frequency power switches and preheating for 5 minutes.

(5) Introducing reaction gas;

after the etching chamber is pumped to the background vacuum (generally 3.0 multiplied by 10 < -3 > Pa or higher), a vacuum meter measuring switch is closed, reaction gases SF 630 sccm and O230 sccm are introduced, a gas inlet hand valve is opened to enable the reaction gases to enter the vacuum chamber, then the vacuum meter is opened to close the high vacuum, and after the flow is stable, the working pressure of the vacuum chamber is adjusted to 1Pa by manually adjusting the opening of a gate valve.

(6) Etching;

first, it is confirmed whether or not electrode cooling water is introduced. After the pressure of the vacuum chamber is stabilized, a radio frequency power supply W1 is started, the plate pressing knob is rotated clockwise, the etching chamber is started to glow, the power is adjusted to 300W, and the C1 adjustment and the C2 adjustment on the matching box are adjusted at the same time, so that the effective power is as large as possible, the reflected power is as small as possible, and good matching is achieved. And starting the radio frequency power supply W2, adjusting the power to be 100W, adjusting the matching, and starting timing.

(7) Sampling;

and sequentially turning off the W2, closing the W1 plate pressure, closing the mass flowmeter and closing the air inlet hand valve. And opening the gate valve, and pumping residual gas in the etching chamber for a period of time. And (3) closing the gate valve VG, opening the inflation valve VINL, lifting the upper cover after the yellow lifting permission indicator lamp on the panel of the central control system is lighted (about 4 minutes), taking out the sample wafer, covering the upper cover, closing the VINL, completely pumping the reaction gas in the pipeline, pumping the reaction chamber to high vacuum, and closing the gate valve. And (4) closing the molecular pump, continuously operating the mechanical pump for 15 minutes, and after the molecular pump stops working, closing the mechanical pump. And turning off the switches of the instruments, turning off the cooling water and turning off the gas source switch of the reaction gas.

Claims (9)

1. The graphene-metal heterojunction photoelectric detector with the concave array is characterized in that: comprising a substrate (1); the substrate (1) is sequentially provided with an insulating layer (2), a growth layer (3) and a graphene layer (4) from bottom to top;

the substrate (1) is provided with one or a plurality of downward concave grooves (11) distributed in an array; a first convex surface (21) which is convex downwards and matched with the groove (11) is arranged on the insulating layer (2); the grooves (11) correspond to the first convex surfaces (21) one by one;

a second convex surface (31) which protrudes downwards and is matched with the inner groove of the first convex surface (21) is arranged on the growth layer (3); the inner grooves of the first convex surfaces (21) correspond to the second convex surfaces (31) one by one;

a third convex surface (41) which is convex downwards and is matched with the inner groove of the second convex surface (31) is arranged on the graphene layer (4); the inner grooves of the second convex surfaces (31) correspond to the third convex surfaces (41) one by one;

an anti-reflection layer (5) is arranged on the inner wall of the inner groove of the third convex surface (41) of the graphene layer (4); and both sides of the inner groove of the third convex surface (41) on the graphene layer (4) are respectively provided with a high work function electrode (6) and a low work function electrode (7) which are formed by wavy interdigital.

2. The concave array graphene-metal heterojunction photodetector of claim 1, wherein: the substrate (1) is provided with downward concave grooves (11) distributed in a 3X3 array.

3. The concave array graphene-metal heterojunction photodetector of claim 1, wherein: the insulating layer (2) adopts a silicon dioxide film.

4. The concave array graphene-metal heterojunction photodetector of claim 1, wherein: the groove (11) is a hemispherical groove.

5. The concave array graphene-metal heterojunction photodetector of claim 1, wherein: the growth layer is formed by depositing Cu or Au or Ag or Mo or Gr at the thickness of 30-70 nm and then depositing Ni at the thickness of 30-70 nm; or a layer of 30-70 nm aluminum oxide directly deposited on the growth layer.

6. The concave array graphene-metal heterojunction photodetector of claim 5, wherein: the graphene layer (4) is a graphene film directly grown on the growth layer (3) by adopting a CVD method; and the number of layers of the graphene film is 1-10.

7. The concave array graphene-metal heterojunction photodetector of claim 6, wherein: the anti-reflection layer (5) is a silicon dioxide film with the thickness of 30-100 nanometers.

8. The concave array graphene-metal heterojunction photodetector of claim 7, wherein: the low work function electrode (7) is made of titanium (Ti), platinum (Pt), manganese (Mn), lithium (Li) or aluminum (Al); the thickness is 50-100 nm.

9. The concave array graphene-metal heterojunction photodetector of claim 8, wherein: the high work function electrode (6) is made of gold (Au), silver (Ag), nickel (Ni) or palladium (Pd) and is 50-100 nanometers thick.

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