Depletion type nickel-zinc-oxygen charged particle detector and preparation method thereof

Abstract

The invention belongs to the technical field of semiconductor device preparation, and discloses a depletion type nickel-zinc-oxygen charged particle detector and a preparation method thereof. The depletion type nickel-zinc-oxygen charged particle detector comprises an aluminum oxide single crystal, a nickel-zinc-oxygen region, a low-resistance zinc oxide region, an insulating layer and a metal electrode. The depletion type nickel-zinc-oxygen charged particle detector is designed, the concentration of a carrier at the back bottom of a detection sensitive region is controlled, the suppression of leakage circuit noise is realized by using a depletion region, meanwhile, the control of a conductive channel is realized, and an effective and simple process manufacturing technology is provided. The preparation problem of an oxide alpha particle detector with a high signal-to-noise ratio characteristic is solved, and the development of a novel depletion type nickel-zinc-oxygen charged particle detector is realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of semiconductor device preparation, and relates to a depletion type nickel-zinc oxide charged particle detector and a preparation method. BACKGROUND

[0002] The semiconductor charged particle detector has important application requirements in industrial detection, medical diagnosis, safety monitoring, space exploration and high-energy physics research, and its advantages mainly include high energy resolution, fast response speed, small size and large-area integration. Meanwhile, compared with the traditional gas detector requiring high voltage operation and the scintillator detector requiring photoelectric conversion, the semiconductor detector significantly reduces the system volume and energy consumption. However, the research and development of the semiconductor charged particle detector still faces three challenges: in the material aspect, the detector based on the traditional narrow-bandgap semiconductor material is prone to signal attenuation due to displacement damage in a strong radiation field; in the signal processing aspect, the charged particles only generate weak charges in the semiconductor, which puts higher requirements on the backend amplification circuit; and in the environmental adaptability aspect, the traditional narrow-bandgap semiconductor detector is easily affected by temperature changes due to the low temperature threshold of thermal excitation caused by the low material bandgap width. In recent years, the wide-bandgap oxide semiconductor (bandgap width greater than 3.0eV) represented by zinc oxide and nickel oxide has become an ideal candidate material for breaking through the limitations of existing technologies due to its excellent intrinsic anti-radiation performance and excellent high-temperature stability. However, in the research and development of the charged particle detector, the oxide semiconductor still faces a series of problems such as difficulty in regulating electrical properties, single device structure, large noise signal and weak response signal.

[0003] In the prior art, a single layer or a heterojunction vertical structure is adopted to prepare a Schottky or PN, PIN junction type device, and such a detector can only collect the electron-hole pairs generated by the signal source as the response signal without an amplification mechanism. In the present application, the depletion type nickel-zinc oxide directly serves as the detection sensitive region, the proportion of nickel atoms and zinc atoms can be controlled to make the nickel-zinc oxide material exhibit a hole conduction type (P type), and the resistivity is adjustable; unlike the vertical device structure, a lateral current amplification mechanism is designed in the present application, that is, an electron conduction type zinc oxide region is prepared on both sides of the hole conduction type nickel-zinc oxide sensitive region, an insulating layer is formed by using the natural depletion of electrons and holes, and the amplification current transport channel is controlled through the contact electrode on the nickel-zinc oxide; at the same time, a same-plane electrode is prepared in the zinc oxide region on both sides of the nickel-zinc oxide detection sensitive region, a voltage is applied, when the response signal causes the resistivity of the region near the nickel-zinc oxide contact electrode to instantaneously decrease, the equivalent amplified current signal is output. As can be seen, the present application directly uses the nickel-zinc oxide as the detection sensitive region to prepare, solves the problem of controllable amplification signal transmission path, can realize high-quality amplification of the detection signal, and the technical innovation is more prominent. SUMMARY

[0004] The present application aims at the key problem of further improving the performance of the oxide charged particle detector, and provides a charged particle detector based on a depletion type nickel-zinc oxide detection sensitive area and capable of realizing signal internal gain characteristics and a preparation method thereof.

[0005] The technical scheme of the present application is as follows:

[0006] A depletion type nickel-zinc oxide charged particle detector, comprising an alumina single crystal 1 (thickness of 360 μm), a nickel-zinc oxide area 2 (concentration of zinc atoms is 1×10 14 cm -3 -1×10 21 cm -3 , concentration of holes is 1×10 14 cm -3 -5×10 18 cm -3 , thickness of 1 μm-100 μm), a low-resistance zinc oxide area 3 (thickness of 1 μm-100 μm, resistivity of 10 -1 -10 5 Ω·cm), an insulating layer 4 (thickness of 0.01 μm-10 μm), a collection electrode 5 (thickness of 0.01 μm-3 μm) and a gate electrode 6 (thickness of 0.01 μm-3 μm).

[0007] The alumina single crystal 1 is provided with a ladder structure composed of the nickel-zinc oxide area 2 of the hole conductive type; the two sides of the ladder structure are the low-resistance zinc oxide area 3, and the nickel-zinc oxide area 2 and the low-resistance zinc oxide area 3 jointly cover the surface of the alumina single crystal 1; the insulating layer 4 is arranged on the surface of the nickel-zinc oxide area 2 and the low-resistance zinc oxide area 3, and a hole is formed on the insulating layer 4, the hole being the collection electrode 5 and the collection electrode 5 being in contact with the low-resistance zinc oxide area 3; a hole is formed at the center position of the insulating layer 4, the hole being the gate electrode 6 and the gate electrode 6 being in contact with the nickel-zinc oxide area 2, and the contact area being the same as the area of the upper surface of the nickel-zinc oxide area 2.

[0008] The ratio of nickel atoms to zinc atoms in the nickel-zinc oxide is between 1000:1-2:1.

[0009] The angle between the waist of the ladder structure and the lower base is 30°-60°.

[0010] A preparation method of a depletion type nickel-zinc oxide charged particle detector, the steps being as follows:

[0011] Step 1: growing the nickel-zinc oxide area 2 on the alumina single crystal 1;

[0012] Step 2: after the photoresist mask on the nickel-zinc oxide area 2, the ladder structure is made by dry etching or wet etching;

[0013] Step 3: After cleaning, low resistance zinc oxide region 3 is prepared by physical deposition or chemical vapor deposition method;

[0014] Step 4: Surface leveling is performed by chemical mechanical polishing or dry etching method to expose the upper surface of nickel zinc oxide region 2 and low resistance zinc oxide region 3;

[0015] Step 5: Insulating layer 4 is prepared by physical deposition method;

[0016] Step 6: After preparing the photoresist mask, the insulating layer 4 in the low resistance zinc oxide region 3 and the nickel zinc oxide region 2 is etched by dry etching or wet etching method to expose the electrode contact part;

[0017] Step 7: After preparing the photoresist mask, the collecting electrode 5 is prepared by physical deposition and mask stripping method;

[0018] Step 8: After preparing the photoresist mask, the gate electrode 6 is prepared by physical deposition and mask stripping method.

[0019] The beneficial effects of the present application: the present application designs a depletion mode nickel zinc oxide charged particle detector, controls the background carrier concentration of the detection sensitive region, and realizes the suppression of leakage current noise; a transverse current amplification mechanism is designed, that is, electron conductive type zinc oxide regions are prepared on both sides of the hole conductive type nickel zinc oxide sensitive region, an insulating layer is formed by using the natural depletion of electrons and holes, and the amplification current transport channel is controlled through the contact electrode on the nickel zinc oxide; the same plane electrode is prepared on the zinc oxide region on both sides of the nickel zinc oxide detection sensitive region, and a voltage is applied, when the response signal causes the resistivity of the region near the nickel zinc oxide contact electrode to instantaneously decrease, the equivalent amplified current signal is output. Therefore, the present application proposes an effective and simple process manufacturing technology, solves the preparation problem of the oxide alpha particle detector with high signal-to-noise ratio characteristics, and realizes the development of a new type of depletion mode nickel zinc oxide charged particle detector. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the charged particle detector based on the depletion mode nickel zinc oxide sensitive region.

[0021] In the figure: 1 alumina single crystal; 2 nickel zinc oxide region; 3 low resistance zinc oxide region; 4 insulating layer; 5 collecting electrode; 6 gate electrode. DETAILED DESCRIPTION

[0022] The specific embodiments of the present application are further described below in combination with the technical solutions and the drawings.

[0023] Example 1

[0024] A preparation method of a depletion mode nickel zinc oxide charged particle detector, comprising the following process steps:

[0025] Step 1: epitaxially growing a 1 μm nickel zinc oxide buried region 2 with a zinc atom concentration of 1×10 14 cm -3 and a hole concentration of 1×10 14 cm -3 on an alumina single crystal with a thickness of 360 μm;

[0026] Step 2: after preparing a photoresist mask, a dry etching is used to make a ladder structure; wherein the angle between the waist of the ladder structure and the lower bottom is 30°;

[0027] Step 3: after cleaning, a chemical vapor deposition is used to prepare a 1 μm low-resistance zinc oxide region 3 with a resistivity of 0.1 Ω·cm, i.e. a zinc oxide layer;

[0028] Step 4: a chemical mechanical polishing method is used to perform surface leveling to expose the nickel zinc oxide buried region 2 and the low-resistance zinc oxide region 3;

[0029] Step 5: a 0.01 μm thick silicon dioxide insulating layer 4 is prepared by using a magnetron sputtering method;

[0030] Step 6: a photoresist mask is prepared, a wet etching method is used to groove in the insulating layer 5 on the nickel zinc oxide region 2 and the zinc oxide region 3 to expose the corresponding part to be deposited electrode;

[0031] Step 7: after preparing a photoresist mask, an electron beam evaporation and a mask stripping method are used to prepare 0.01 μm thick aluminum electrodes 5 and 6.

[0032] Embodiment 2

[0033] A preparation method of a depletion mode nickel zinc oxide band particle detector, comprising the following process steps:

[0034] Step 1: epitaxially growing a 30 μm nickel zinc oxide buried region 2 with a zinc atom concentration of 1×10 19 cm -3 and a hole concentration of 1×10 16 cm -3 on an alumina single crystal with a thickness of 360 μm;

[0035] Step 2: after preparing a photoresist mask, a dry etching is used to make a ladder structure; wherein the angle between the waist of the ladder structure and the lower bottom is 60°;

[0036] Step 3: after cleaning, a chemical vapor deposition is used to prepare a 30 μm low-resistance zinc oxide region 3 with a resistivity of 0.5 Ω·cm, i.e. a zinc oxide layer;

[0037] Step 4: Surface leveling by chemical mechanical polishing to expose the buried NiZnO region 2 and the low resistance ZnO region 3;

[0038] Step 5: A 1 μm thick SiO2 insulating layer 4 is prepared by magnetron sputtering;

[0039] Step 6: A photoresist mask is prepared, and a groove is etched in the insulating layer 5 on the NiZnO region 2 and the ZnO region 3 by wet etching to expose the part to be deposited electrode;

[0040] Step 7: After the photoresist mask is prepared, an Al electrode 5 and an Al electrode 6 with a thickness of 1 μm are prepared by electron beam evaporation and mask stripping.

[0041] Example 3

[0042] A preparation method of a depletion mode NiZnO band particle detector, comprising the following process steps:

[0043] Step 1: A buried NiZnO region 2 with a thickness of 100 μm, a zinc atomic concentration of 1×10 21 cm -3 , and a hole concentration of 5×10 18 cm -3 is epitaxially grown on an alumina single crystal with a thickness of 360 μm;

[0044] Step 2: After the photoresist mask is prepared, a ladder structure is prepared by dry etching; wherein the angle between the waist of the ladder structure and the lower bottom is 50°;

[0045] Step 3: After cleaning, a low resistance ZnO region 3 with a thickness of 100 μm and a resistivity of 10 5 Ω·cm is prepared by chemical vapor deposition, which is a ZnO layer;

[0046] Step 4: Surface leveling by chemical mechanical polishing to expose the buried NiZnO region 2 and the low resistance ZnO region 3;

[0047] Step 5: A 10 μm thick SiO2 insulating layer 4 is prepared by magnetron sputtering;

[0048] Step 6: A photoresist mask is prepared, and a groove is etched in the insulating layer 5 on the NiZnO region 2 and the ZnO region 3 by wet etching to expose the part to be deposited electrode;

[0049] Step 7: After the photoresist mask is prepared, an Al electrode 5 and an Al electrode 6 with a thickness of 3 μm are prepared by electron beam evaporation and mask stripping.

Claims

1. A depletion-type nickel-zinc-oxygen charged particle detector, characterized in that, The structure of this depletion-type nickel-zinc-oxygen charged particle detector is as follows: The surface of the alumina single crystal (1) is provided with a stepped structure composed of a nickel-zinc-oxygen region (2) of the hole-conducting type; the two sides of the stepped structure are low-resistivity zinc oxide regions (3), and the nickel-zinc-oxygen region (2) and the low-resistivity zinc oxide region (3) together cover the surface of the alumina single crystal (1); an insulating layer (4) is provided on the surface of the nickel-zinc-oxygen region (2) and the low-resistivity zinc oxide region (3), and an opening is made in the insulating layer (4), the opening is a collecting electrode (5), and the collecting electrode (5) is in contact with the low-resistivity zinc oxide region (3); An opening is made at the center of the insulating layer (4), and the opening is the gate electrode (6). The gate electrode (6) is in contact with the nickel-zinc-oxygen region (2), and the contact area is the same as the area of ​​the upper surface of the nickel-zinc-oxygen region (2).

2. The depletion-type nickel-zinc-oxygen charged particle detector according to claim 1, characterized in that, The thickness of the alumina single crystal (1) is 360 μm; The concentration of zinc atoms in the nickel-zinc-oxygen region (2) is 1×10⁻⁶. 14 cm -3 -1×10 21 cm -3 The hole concentration is 1×10 14 cm -3 -5×10 18 cm -3 The thickness ranges from 1μm to 100μm. The thickness of the low-resistivity zinc oxide region (3) is 1μm-100μm, and the resistivity is 10. -1 -10 5 Ω·cm; The thickness of the insulating layer (4) is 0.01μm-10μm; The thickness of the collecting electrode (5) is 0.01 μm-3 μm; The thickness of the gate electrode (6) is 0.01μm-3μm.

3. The depletion-type nickel-zinc-oxygen charged particle detector according to claim 1, characterized in that, The ratio of nickel atoms to zinc atoms in nickel-zinc-oxygen alloys is between 1000:1 and 2:

1.

4. The depletion-type nickel-zinc-oxygen charged particle detector according to claim 1, characterized in that, The angle between the waist and the bottom of the tiered structure is 30°-60°.

5. A method for fabricating a depletion-type nickel-zinc-oxygen charged particle detector, characterized in that, The steps are as follows: Step 1: Grow a nickel-zinc-oxygen region (2) on an alumina single crystal (1); Step 2: After applying a photoresist mask to the nickel-zinc-oxygen region (2), the ladder structure is fabricated by dry etching or wet etching. Step 3: After cleaning, prepare low-resistivity zinc oxide regions using physical deposition or chemical vapor deposition methods (3); Step 4: Use chemical mechanical polishing or dry etching to smooth the surface and expose the upper surfaces of the nickel-zinc oxide region (2) and the low-resistivity zinc oxide region (3); Step 5: Prepare the insulating layer (4) using physical deposition method; Step 6: Prepare a photoresist mask and use dry etching or wet etching to cut grooves in the insulating layer (4) on the low-resistivity zinc oxide region (3) and the nickel zinc oxide region (2) to expose the part to be contacted by the electrode. Step 7: After preparing the photoresist mask, the collecting electrode is prepared by physical deposition and mask stripping (5); Step 8: After preparing the photoresist mask, the gate electrode is prepared by physical deposition and mask stripping (6).

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