CN113488359A - Preparation method of refrigeration type GaN electron source used in ultrahigh vacuum system - Google Patents
Preparation method of refrigeration type GaN electron source used in ultrahigh vacuum system Download PDFInfo
- Publication number
- CN113488359A CN113488359A CN202110634915.8A CN202110634915A CN113488359A CN 113488359 A CN113488359 A CN 113488359A CN 202110634915 A CN202110634915 A CN 202110634915A CN 113488359 A CN113488359 A CN 113488359A
- Authority
- CN
- China
- Prior art keywords
- gan
- electron source
- ultrahigh vacuum
- vacuum system
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
- H01J1/02—Main electrodes
- H01J1/34—Photo-emissive cathodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J40/00—Photoelectric discharge tubes not involving the ionisation of a gas
- H01J40/02—Details
- H01J40/04—Electrodes
- H01J40/06—Photo-emissive cathodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J7/00—Details not provided for in the preceding groups and common to two or more basic types of discharge tubes or lamps
- H01J7/24—Cooling arrangements; Heating arrangements; Means for circulating gas or vapour within the discharge space
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
- H01J9/02—Manufacture of electrodes or electrode systems
- H01J9/12—Manufacture of electrodes or electrode systems of photo-emissive cathodes; of secondary-emission electrodes
Abstract
The invention provides a preparation method of a refrigeration type GaN electron source used in an ultrahigh vacuum system. The preparation method of the refrigeration type GaN electron source mainly utilizes an indium welding technology, after the surface of GaN is cleaned by adopting a chemical cleaning and thermal annealing process, a GaN sample is welded with a semiconductor refrigeration sheet and a thermocouple, and then a cesium and oxygen activation process is utilized to activate the GaN to reach the surface with negative electron affinity, so that the preparation of the electron source is completed. The method utilizes the semiconductor refrigeration technology to slow down the temperature rise rate of the cathode, has the advantages of small volume, good controllability, high reliability and the like, and can effectively prolong the service life of the negative electron affinity GaN electron source used in the ultrahigh vacuum system.
Description
Technical Field
The invention relates to the technical field of semiconductor materials, in particular to a preparation method of a refrigeration type GaN electron source used in an ultrahigh vacuum system.
Background
Gallium nitride (GaN) is an extremely stable semiconductor material, and has excellent characteristics such as wide bandgap, low dielectric constant, corrosion resistance, high temperature resistance, radiation resistance and the like. The negative electron affinity GaN-based photocathode has the advantages of high quantum efficiency, small dark current, concentrated emitted electron energy distribution and the like, is a novel high-performance ultraviolet photocathode, and is widely applied to the fields of ultraviolet vacuum detection, high-energy physics, microelectronic technology, electron beam plane printing, electron microscope and the like.
When the negative electron affinity GaN-based electron source operates, the laser illumination power density is high, the GaN surface temperature can be on the market after long-time laser irradiation, and the cesium and oxygen activated layers on the surface can be damaged even a GaN sample can be damaged due to overhigh temperature, so that the service life of the GaN-based electron source is shortened
The peltier effect means that when a current passes through a loop formed by different conductors, in addition to irreversible joule heat generation, heat absorption and heat release phenomena occur at joints of the different conductors respectively along with the difference of current directions. The semiconductor refrigerating sheet based on the principle has the advantage of no sliding part, so that the semiconductor refrigerating sheet can be applied to occasions with limited space, high reliability requirement and no refrigerant pollution. The semiconductor refrigerating plate works by using direct current, which can refrigerate and heat, and realizes refrigeration or heating on the same refrigerating plate by changing the polarity of the direct current.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a preparation method of a refrigeration type GaN electron source used in an ultrahigh vacuum system
In order to achieve the purpose, the invention adopts the technical scheme that:
a refrigeration type GaN electron source used in an ultrahigh vacuum system is characterized in that a photocathode comprises a cesium-oxygen activated layer, a thermocouple, a GaN sample, an indium welding layer and a semiconductor refrigeration piece from the surface to the bottom layer by layer.
Furthermore, the thermocouple is attached to the side face of the GaN sample in a welding mode.
Furthermore, the semiconductor refrigeration piece is suitable for ultrahigh vacuum conditions.
Further, the method comprises the following steps:
step one, chemically cleaning a GaN sample by using strong acid, organic solvent and strong oxidant (sulfuric acid, carbon tetrachloride, acetone, absolute ethyl alcohol, deionized water, hydrogen peroxide and the like);
completely removing oxides and other pollutants on the surface of the GaN by using a thermal annealing process to achieve an atomic-level clean surface;
step three, welding the GaN sample with a thermocouple;
welding the GaN sample and the semiconductor refrigerating sheet under the ultrahigh vacuum condition;
and step five, carrying out color oxygen activation on the GaN surface, independently activating the Cs for a period of time until the photocurrent reaches the maximum value, then continuing the Cs source, and discontinuously carrying out Cs/O alternate activation by the O source.
Furthermore, in the step one, a proper chemical cleaning method and a proper chemical cleaning reagent are selected.
Further, in the second step, the maximum heating temperature needs to be set reasonably. At this temperature it should be ensured that oxides and other contaminants on the GaN surface are completely removed.
Further, in the second step, the time required to be kept at the highest temperature needs to be reasonably set. During the time, the oxides and other pollutants on the GaN surface can be completely removed, and the carbon content is reduced to a certain degree.
Furthermore, in the second step, the rising rate from room temperature to temperature at the beginning of heating and the falling rate from temperature to room temperature after the end of heating and purification are set reasonably.
Furthermore, in the second step, the thickness of the indium foil is 25-100 μm and the amount of indium is controlled.
Furthermore, in the second step, the indium welding can be started only after the vacuum degree of the indium welding test bed is better than a certain degree.
The invention has the advantages that: by utilizing the semiconductor refrigeration technology, the problems that the temperature of the surface of a GaN electron source material is increased at a very high speed due to the high-power laser loading, the quantum efficiency is reduced due to the fact that the active layer of the GaN electron source material is damaged by high temperature, and the service life of the GaN electron source with negative electron affinity in an ultrahigh vacuum system is shortened are solved, and the service life of the GaN electron source with negative electron affinity in the ultrahigh vacuum system can be effectively prolonged.
Drawings
FIG. 1 is a flow of preparation of a refrigeration type GaN electron source for an ultrahigh vacuum system.
Detailed Description
Examples
The invention will be further described with reference to the following drawings and specific embodiments.
And (3) ultrasonically cleaning the GaN sample for 5min by using carbon tetrachloride, acetone, absolute ethyl alcohol and deionized water respectively.
The samples were then mixed in a volume ratio of 4: 1: 1 concentrated H2SO4，H2O2And washing the mixed solution with deionized water at 90 ℃ for 10 min.
And performing ultrasonic cleaning for 5min by using deionized water to finish chemical cleaning.
The maximum temperature was set at 710 ℃ under ultra-high vacuum.
The first 20min is that the set temperature is linearly increased from 0 ℃ to 200 ℃ for 20-80 min, the set temperature is linearly increased from 200 ℃ to 550 ℃ for 80-160 min, the set temperature is linearly increased from 550 ℃ to 710 ℃ for 160-180 min, the temperature is stabilized at 710 ℃, the temperature is decreased from 180-240 min, the set temperature is linearly decreased from 710 ℃ to 300 ℃, then the temperature is naturally cooled, and the temperature is decreased to about 75 ℃ for about 1h, so that the oxides on the surface of the GaN are completely removed.
And (5) attaching and connecting the thermocouple and the GaN sample by using tin-lead welding.
30V is selected as the working voltage of the ceramic heater during indium welding, the balance temperature of the end face of the semiconductor cooling piece during welding is 300 ℃, and the holding time is 1 h.
And in the first 40min, setting the temperature of the end face of the semiconductor refrigerating piece to gradually rise and approach 300 ℃. And setting the temperature of the end face of the semiconductor refrigerating piece to be about 300 ℃ for about 1 hour from 40-100 min. Then naturally cooling to room temperature in a vacuum chamber;
and then, carrying out color oxygen activation on the GaN surface, independently activating the Cs for a period of time until the photocurrent reaches the maximum value, then continuing the Cs source, and discontinuously carrying out Cs/O alternate activation by the O source.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.
Claims (10)
1. A refrigeration type GaN electron source used in an ultrahigh vacuum system is characterized in that a photocathode comprises a cesium-oxygen activated layer, a thermocouple, a GaN sample, an indium welding layer and a semiconductor refrigeration piece from the surface to the bottom layer by layer.
2. The refrigeration type GaN electron source used in the ultrahigh vacuum system of claim 1, wherein the thermocouple is attached to the side of the GaN sample by welding.
3. The refrigerating GaN electron source of claim 1, wherein the semiconductor refrigerating plate is suitable for use in ultra-high vacuum conditions.
4. The method for preparing the refrigeration type GaN electron source used in the ultrahigh vacuum system according to any one of claims 1 to 3, characterized by comprising the following steps:
step one, chemically cleaning a GaN sample by using strong acid, organic solvent and strong oxidant (sulfuric acid, carbon tetrachloride, acetone, absolute ethyl alcohol, deionized water, hydrogen peroxide and the like);
completely removing oxides and other pollutants on the surface of the GaN by using a thermal annealing process to achieve an atomic-level clean surface;
step three, welding the GaN sample with a thermocouple;
welding the GaN sample and the semiconductor refrigerating sheet under the ultrahigh vacuum condition;
and step five, activating the GaN surface, wherein Cs is independently activated for a period of time until the photocurrent reaches the maximum value, then the Cs source is continued, and the O source is discontinuously activated alternately by Cs/O.
5. The method for preparing the refrigeration type GaN electron source in the ultrahigh vacuum system as claimed in claim 4, wherein in the first step, a proper chemical cleaning method and a proper chemical cleaning reagent are selected.
6. The method for preparing the refrigeration type GaN electron source in the ultrahigh vacuum system as claimed in claim 4, wherein the maximum heating temperature in step two is set reasonably. At this temperature it should be ensured that oxides and other contaminants on the GaN surface are completely removed.
7. The method for preparing the refrigeration type GaN electron source in the ultrahigh vacuum system as claimed in claim 4, wherein the time required to be kept at the highest temperature in the second step is set reasonably. During the time, the oxides and other pollutants on the GaN surface can be completely removed, and the carbon content is reduced to a certain degree.
8. The method as claimed in claim 4, wherein the second step is carried out by setting the rising rate from room temperature to temperature at the beginning of heating and the falling rate from temperature to room temperature after the heating and purifying are finished.
9. The method as claimed in claim 4, wherein the thickness of the indium foil in the fifth step is 25-100 μm and the amount of indium is controlled.
10. The method for preparing the refrigeration type GaN electron source in the ultrahigh vacuum system as claimed in claim 4, wherein in the fifth step, the indium soldering test bench is required to reasonably set the rising rate from room temperature to temperature at the beginning of heating and the falling rate from temperature to room temperature after the heating and purification are finished. The vacuum degree of the welding wire is better than a certain degree, and then the indium welding can be started.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110634915.8A CN113488359A (en) | 2021-06-08 | 2021-06-08 | Preparation method of refrigeration type GaN electron source used in ultrahigh vacuum system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110634915.8A CN113488359A (en) | 2021-06-08 | 2021-06-08 | Preparation method of refrigeration type GaN electron source used in ultrahigh vacuum system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113488359A true CN113488359A (en) | 2021-10-08 |
Family
ID=77934765
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110634915.8A Pending CN113488359A (en) | 2021-06-08 | 2021-06-08 | Preparation method of refrigeration type GaN electron source used in ultrahigh vacuum system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113488359A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1096398A (en) * | 1993-04-05 | 1994-12-14 | 佳能株式会社 | Electron source and manufacture method thereof and the image processing system that uses described electron source |
| JP2003346691A (en) * | 2002-05-24 | 2003-12-05 | National Institute For Materials Science | Cathode for cooling type high quantum efficiency photocathode (type) electron ray source |
| CN104112634A (en) * | 2014-07-23 | 2014-10-22 | 四川天微电子有限责任公司 | NEA photoelectric cathode preparation process |
| CN104124308A (en) * | 2014-07-23 | 2014-10-29 | 四川天微电子有限责任公司 | Photoelectric cathode manufacturing process |
| CN106568230A (en) * | 2016-10-18 | 2017-04-19 | 中国电子科技集团公司第五十五研究所 | InGaAs photoelectric cathode refrigeration device based on semiconductor refrigeration piece |
-
2021
- 2021-06-08 CN CN202110634915.8A patent/CN113488359A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1096398A (en) * | 1993-04-05 | 1994-12-14 | 佳能株式会社 | Electron source and manufacture method thereof and the image processing system that uses described electron source |
| JP2003346691A (en) * | 2002-05-24 | 2003-12-05 | National Institute For Materials Science | Cathode for cooling type high quantum efficiency photocathode (type) electron ray source |
| CN104112634A (en) * | 2014-07-23 | 2014-10-22 | 四川天微电子有限责任公司 | NEA photoelectric cathode preparation process |
| CN104124308A (en) * | 2014-07-23 | 2014-10-29 | 四川天微电子有限责任公司 | Photoelectric cathode manufacturing process |
| CN106568230A (en) * | 2016-10-18 | 2017-04-19 | 中国电子科技集团公司第五十五研究所 | InGaAs photoelectric cathode refrigeration device based on semiconductor refrigeration piece |
Non-Patent Citations (1)
| Title |
|---|
| 乔建良等: "负电子亲和势GaN真空面电子源研究进展", 《物理学报》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110265504B (en) | Ultraviolet photoelectric detector and preparation method thereof | |
| CN1933096B (en) | Low-temperature chip direct bonding method | |
| JP2015535141A (en) | GalnAsSb solid solution based heterostructure, method of manufacturing the heterostructure, and light emitting diode based on the heterostructure | |
| Feng et al. | Optimized chemical cleaning procedure for enhancing photoemission from GaAs photocathode | |
| CN102000893B (en) | Eutectic microwelding method for LED crystals | |
| CN113488359A (en) | Preparation method of refrigeration type GaN electron source used in ultrahigh vacuum system | |
| CN105364284A (en) | Low-temperature quick welding method for zirconia or zirconia-based composite materials | |
| CN108070891A (en) | A kind of graphene carbon nanotube composite film and preparation method and application | |
| CN105845552A (en) | Photoelectrochemical etching method for removing SiC substrate epitaxial graphene buffer layer | |
| CN103001119A (en) | Inverted laser chip based on SiC substrate and manufacturing method of inverted laser chip | |
| US10535789B2 (en) | Refrigeration from graphene-based nanoemitters | |
| CN109461682B (en) | Wet oxidation device and application method thereof | |
| CN109507006B (en) | Layer-by-layer etching method applied to photoluminescence test of VCSEL structure epitaxial wafer and VCSEL structure epitaxial wafer | |
| CN104377543A (en) | Method for manufacturing semiconductor laser endoscope | |
| Shiraz et al. | The effect of a porous layer on IV characterization of a polysilicon pn junction | |
| CN109904064A (en) | A method of improving carbonization Si direct bonding intensity | |
| Liu et al. | High current density GaN∕ CsBr heterojunction photocathode with improved photoyield | |
| CN105513948B (en) | A kind of method of modifying on GaAs material surface | |
| KR101418004B1 (en) | The etching method of silicon carbide by oxidizing agent additive molten salt | |
| CN101285209A (en) | Photoelectrochemical etching device for n -type silicium | |
| JP5988299B2 (en) | Semiconductor device manufacturing method | |
| CN103545403A (en) | Photo-assisted LED wet coarsening equipment | |
| CN116813366A (en) | Hamburger type ceramic-crystal composite substrate and preparation method thereof | |
| Wang et al. | Study on New Type of Double-Sided Cooling Packaging Technology for Semiconductor Lasers | |
| US11827997B2 (en) | Stripping method and stripping device for silicon carbide single crystal wafers |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20211008 |