Single-crystal beta-Ga.SUB.2.O.SUB.3 .MSM detector and preparation method thereof

Abstract

A single-crystal β-Ga.sub.2O.sub.3 MSM detector and a preparation method thereof, comprising: machining grooves on a single-crystal β-Ga.sub.2O.sub.3 substrate using a laser-assisted waterjet machining technique to form a 3D shape; wet etching the machined single-crystal β-Ga.sub.2O.sub.3 substrate using an HF solution to remove machining damage; performing Au evaporation on a surface of the single-crystal β-Ga.sub.2O.sub.3 substrate after processing, coating an Au thin film on the surface of the single-crystal β-Ga.sub.2O.sub.3 substrate; and grinding the surface of the single-crystal β-Ga.sub.2O.sub.3 substrate after evaporation to remove the Au thin film on an undressed surface and retain the Au thin film in the grooves, and then obtaining the single-crystal β-Ga.sub.2O.sub.3 MSM detector.

Claims

1. A method for preparing a single-crystal β-Ga.sub.2O.sub.3 MSM detector is provided, comprising the following steps: machining grooves on a single-crystal β-Ga.sub.2O.sub.3 substrate using a laser-assisted waterjet machining technique to form a 3D shape; wet etching the machined single-crystal β-Ga.sub.2O.sub.3 substrate using an HF (Hydrofluoric Acid) solution to remove machining damage; performing Au evaporation on a surface of the single-crystal β-Ga.sub.2O.sub.3 substrate after processing, coating an Au thin film on the surface of the single-crystal β-Ga.sub.2O.sub.3 substrate; and grinding the surface of the single-crystal β-Ga.sub.2O.sub.3 substrate after evaporation to remove the Au thin film on an undressed surface and retain the Au thin film in the grooves, then obtaining the single-crystal β-Ga.sub.2O.sub.3 MSM detector.

2. The method for preparing the single-crystal β-Ga.sub.2O.sub.3 MSM detector according to claim 1, wherein: the groove is an inverted trapezoidal groove.

3. The method for preparing the single-crystal β-Ga.sub.2O.sub.3 MSM detector according to claim 1, wherein: in the laser-assisted waterjet machining technique, a pulse width of a nanosecond laser is 10-350 ns, a pulse repetition frequency is 20-1000 kHz, a scanning speed is 1-16 mm/s, and a waterjet pressure is 4-16 MPa.

4. The method for preparing the single-crystal β-Ga.sub.2O.sub.3 MSM detector according to claim 3, wherein: a wavelength of the nanosecond laser is 1064 nm.

5. The method for preparing the single-crystal β-Ga.sub.2O.sub.3 MSM detector according to claim 3, wherein: single-pulse energy of the nanosecond laser is 0.02-0.1 mJ, a height of a focal plane is −0.1-0.1 mm.

6. The method for preparing the single-crystal β-Ga.sub.2O.sub.3 MSM detector according to claim 1, wherein: in the laser-assisted waterjet machining technique, a target distance of a nozzle of the waterjet is 0.3-1.4 mm, an offset distance of the waterjet is 0.3-0.7 mm, and an impact angle of the waterjet is 39°-51°.

7. The method for preparing the single-crystal β-Ga.sub.2O.sub.3 MSM detector according to claim 1, wherein: a concentration of the HF solution for the wet etching is 47-49%.

8. The method for preparing the single-crystal β-Ga.sub.2O.sub.3 MSM detector according to claim 1, wherein: an etching temperature is 5-25° C., and an etching time is 8-15 min.

9. The method for preparing the single-crystal β-Ga.sub.2O.sub.3 MSM detector according to claim 1, wherein: a grinding fluid used for the grinding is a 1-2.5 μm of Al.sub.2O.sub.3 grinding fluid, a grinding disc is a softer grinding disc made of lead.

10. A 3D single-crystal β-Ga.sub.2O.sub.3 MSM detector, being prepared by the preparation method of any one of claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary examples of the present invention and descriptions thereof are used to explain the present invention, and do not constitute an improper limitation of the present invention.

(2) FIG. 1 is a schematic diagram of a surface structure of a prepared single-crystal β-Ga.sub.2O.sub.3 MSM detector;

(3) FIG. 2 is a process flow diagram of preparing the single-crystal β-Ga.sub.2O.sub.3 MSM detector of examples of the present invention, wherein, (a) is a single-crystal β-Ga.sub.2O.sub.3 substrate to be machined, (b) is a schematic diagram of a structure of the MSM detector after laser-assisted waterjet machining and wet etching, (c) is a schematic diagram of a surface of the substrate coated with an Au thin film after evaporation, and (d) is a schematic diagram of the prepared MSM detector after grinding and polishing; and

(4) FIG. 3 is a diagram of a surface shape of the single-crystal β-Ga.sub.2O.sub.3 machined by the laser-assisted waterjet machining in Example 1, wherein, B is a partial enlargement of A.

DETAILED DESCRIPTION

(5) It should be pointed out that the following detailed descriptions are all illustrative and are intended to provide further descriptions of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as those usually understood by a person of ordinary skill in the art to which the present invention belongs.

(6) The present invention will now be further described with reference to the accompanying drawings and examples.

Example 1

(7) As shown in FIG. 2, a method for preparing a single-crystal β-Ga.sub.2O.sub.3 MSM detector, comprising the steps of:

(8) 1) Machining to prepare an inverted trapezoidal crossed groove structure using a laser-assisted waterjet.

(9) The present process uses a nanosecond laser with a wavelength of 1064 nm, a laser pulse width of 30 ns and a pulse frequency of 315 kHz.

(10) (1) cleaning a single-crystal β-Ga.sub.2O.sub.3 substrate with ultrasonic cleaning, and mounting the cleaned substrate on a laser-assisted waterjet transparent workbench;

(11) (2) focusing the device to a height of a focal plane of the laser of 0 mm; adjusting the relative position of the laser and the waterjet to an angle of the waterjet of 45°, an offset distance of the waterjet of 0.5 mm and a target distance of a nozzle of the waterjet of 0.6 mm;

(12) (3) setting the laser parameters to a pulse width of 30 ns, a pulse frequency of 315 kHz, an average power of the laser of 20 W, a scanning speed of 1 mm/s, a machining times of once and a lateral offset distance of 10 μm;

(13) (4) adjusting a waterjet pressure of 6 MPa; and

(14) (5) running a machining program for MSM structure machining, and obtaining the inverted trapezoidal groove after the machining with a depth of 15-25 μm and a width of 50-60 μm; a diagram of a shape of the single-crystal β-Ga.sub.2O.sub.3 machined by the laser-assisted waterjet machining, as shown in FIG. 3.

(15) 2) Wet etching on the machined single-crystal β-Ga.sub.2O.sub.3.

(16) The etching solution used for the present process is an HF solution with a solution concentration of 47-49% and an etching temperature of 5-25° C.

(17) (1) cleaning and placing the single-crystal β-Ga.sub.2O.sub.3 substrate in a beaker;

(18) (2) preparing the HF solution with a solubility of 49%;

(19) (3) pouring the prepared HF solution into the beaker until the substrate is submerged and reacting for 10 min at room temperature (20° C.); and

(20) (4) taking out and cleaning the substrate.

(21) 3) Evaporation of the single-crystal β-Ga.sub.2O.sub.3.

(22) (1) mounting the processed single-crystal β-Ga.sub.2O.sub.3 substrate on an evaporation workbench;

(23) (2) evaporating a surface of the single-crystal β-Ga.sub.2O.sub.3 substrate with a layer of nanoscale Au thin film; and

(24) (3) taking out the substrate.

(25) 4) Grinding of the single-crystal β-Ga.sub.2O.sub.3.

(26) A grinding fluid used in the present process is 1 μm of Al.sub.2O.sub.3 grinding fluid, and a grinding disc is a softer grinding disc made of lead.

(27) (1) mounting the single-crystal β-Ga.sub.2O.sub.3 substrate on a grinding workbench;

(28) (2) mounting the grinding disc made of lead, and spraying the 1 μm of Al.sub.2O.sub.3 grinding liquid on the grinding disc made of lead;

(29) (3) starting the grinding equipment for grinding;

(30) (4) taking out the single-crystal β-Ga.sub.2O.sub.3 substrate after grinding for a period of time and observing under a microscope whether the Au thin film on the micro-machined surface is completely removed, and if it is not completely removed, continuing the grinding until it is completely removed; and

(31) (5) cleaning the grinded single-crystal β-Ga.sub.2O.sub.3 substrate, and then obtaining the single-crystal β-Ga.sub.2O.sub.3 MSM detector.

Example 2

(32) A method for preparing a single-crystal β-Ga.sub.2O.sub.3 MSM detector, comprising the steps of:

(33) 1) Machining to prepare an inverted trapezoidal crossed groove structure using a laser-assisted waterjet.

(34) The present process uses a nanosecond laser with a wavelength of 1064 nm, a laser pulse width of 20 ns and a pulse frequency of 490 kHz.

(35) (1) cleaning a single-crystal β-Ga.sub.2O.sub.3 substrate with ultrasonic cleaning, and mounting the cleaned substrate on a laser-assisted waterjet transparent workbench;

(36) (2) focusing the device to a height of a focal plane of the laser of −0.1 mm; adjusting the relative position of the laser and the waterjet to an angle of the waterjet of 45°, an offset distance of the waterjet of 0.5 mm and a target distance of a nozzle of the waterjet of 0.6 mm;

(37) (3) setting the laser parameters to a pulse width of 20 ns, a pulse frequency of 490 kHz, an average power of the laser of 25 W, a scanning speed of 1 mm/s, a machining times of twice and a lateral offset distance of 15 μm;

(38) (4) adjusting a waterjet pressure of 6 MPa; and

(39) (5) running a machining program for MSM structure machining, and obtaining the inverted trapezoidal groove after the machining with a depth of 20-30 μm and a width of 60-70 μm.

(40) 2) Wet etching on the machined single-crystal β-Ga.sub.2O.sub.3.

(41) The etching solution used for the present process is an HF solution with a solution concentration of 47-49% and an etching temperature of 5-25° C.

(42) (1) cleaning and placing the single-crystal β-Ga.sub.2O.sub.3 substrate in a beaker;

(43) (2) preparing the HF solution with a solubility of 47%;

(44) (3) pouring the prepared HF solution into the beaker until the substrate is submerged and reacting for 10 min at room temperature (25° C.); and

(45) (4) taking out and cleaning the substrate.

(46) 3) Evaporation of the single-crystal β-Ga.sub.2O.sub.3.

(47) (1) mounting the processed single-crystal β-Ga.sub.2O.sub.3 substrate on an evaporation workbench;

(48) (2) evaporating a surface of the single-crystal β-Ga.sub.2O.sub.3 substrate with a layer of nanoscale Au thin film; and

(49) (3) taking out the substrate.

(50) 4) Grinding of the single-crystal β-Ga.sub.2O.sub.3.

(51) A grinding fluid used in the present process is 1 μm of Al.sub.2O.sub.3 grinding fluid, and a grinding disc is a softer grinding disc made of lead.

(52) (1) mounting the single-crystal β-Ga.sub.2O.sub.3 substrate on a grinding workbench;

(53) (2) mounting the grinding disc made of lead, and spraying the 1 μm of Al.sub.2O.sub.3 grinding liquid on the grinding disc made of lead;

(54) (3) starting the grinding equipment for grinding;

(55) (4) taking out the single-crystal β-Ga.sub.2O.sub.3 substrate after grinding for a period and observing under a microscope whether the Au thin film on the micro-machined surface is completely removed, and if it is not completely removed, continuing the grinding until it is completely removed; and

(56) (5) cleaning the grinded single-crystal β-Ga.sub.2O.sub.3 substrate, and then obtaining the single-crystal β-Ga.sub.2O.sub.3 MSM detector.

Example 3

(57) A method for preparing a single-crystal β-Ga.sub.2O.sub.3 MSM detector, comprising the steps of:

(58) 1) Machining to prepare an inverted trapezoidal crossed groove structure using a laser-assisted waterjet.

(59) The present process uses a nanosecond laser with a wavelength of 1064 nm, a laser pulse width of 10 ns and a pulse frequency of 1000 kHz.

(60) (1) cleaning a single-crystal β-Ga.sub.2O.sub.3 substrate with ultrasonic cleaning, and mounting the cleaned substrate on a laser-assisted waterjet transparent workbench;

(61) (2) focusing the device to a height of a focal plane of the laser of 0.1 mm; adjusting the relative position of the laser and the waterjet to an angle of the waterjet of 45°, an offset distance of the waterjet of 0.5 mm and a target distance of a nozzle of the waterjet of 0.6 mm;

(62) (3) setting the laser parameters to a pulse width of 10 ns, a pulse frequency of 1000 kHz, an average power of the laser of 30 W, a scanning speed of 1 mm/s, a machining times of 3 times and a lateral offset distance of 10 μm;

(63) (4) adjusting a waterjet pressure of 6 MPa; and

(64) (5) running a machining program for MSM structure machining, and obtaining the inverted trapezoidal groove after the machining with a depth of 10-15 μm and a width of 50-60 μm.

(65) 2) Wet etching on the machined single-crystal β-Ga.sub.2O.sub.3.

(66) The etching solution used for the present process is an HF solution with a solution concentration of 47-49% and an etching temperature of 5-25° C.

(67) (1) cleaning and placing the single-crystal β-Ga.sub.2O.sub.3 substrate in a beaker;

(68) (2) preparing the HF solution with a solubility of 47%;

(69) (3) pouring the prepared HF solution into the beaker until the substrate is submerged and reacting for 10 min at room temperature (15° C.); and

(70) (4) taking out and cleaning the substrate.

(71) 3) Evaporation of the single-crystal β-Ga.sub.2O.sub.3.

(72) (1) mounting the processed single-crystal β-Ga.sub.2O.sub.3 substrate on an evaporation workbench;

(73) (2) evaporating a surface of the single-crystal β-Ga.sub.2O.sub.3 substrate with a layer of nanoscale Au thin film; and

(74) (3) taking out the substrate.

(75) 4) Grinding of the single-crystal β-Ga.sub.2O.sub.3.

(76) A grinding fluid used in the present process is 1 μm of Al.sub.2O.sub.3 grinding fluid, and a grinding disc is a softer grinding disc made of lead.

(77) (1) mounting the single-crystal β-Ga.sub.2O.sub.3 substrate on a grinding workbench;

(78) (2) mounting the grinding disc made of lead, and spraying the 1 μm of Al.sub.2O.sub.3 grinding liquid on the grinding disc made of lead;

(79) (3) starting the grinding equipment for grinding;

(80) (4) taking out the single-crystal β-Ga.sub.2O.sub.3 substrate after grinding for a period of time and observing under a microscope whether the Au thin film on the micro-machined surface is completely removed, and if it is not completely removed, continuing the grinding until it is completely removed; and

(81) (5) cleaning the grinded single-crystal β-Ga.sub.2O.sub.3 substrate, and then obtaining the single-crystal β-Ga.sub.2O.sub.3 MSM detector.

(82) The foregoing descriptions are merely preferred examples of the present invention but are not intended to limit the present invention. A person skilled in art may make various alterations and variations to the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principles of the present invention shall fall within the protection scope of the present invention.