A method for forming ohmic contact of (100) oriented n-type single crystal diamond electrode

Abstract

The invention discloses an ohmic contact forming method for a (100) oriented n-type monocrystalline diamond electrode. The problems of difficulty in ohmic preparation of (100) oriented n-type monocrystalline diamond and high specific contact resistivity in the prior art are solved. The forming method comprises the following steps: S1, grinding and polishing the surface of (100)-oriented n-type monocrystalline diamond to obtain a smooth surface; S2, growing an n-type monocrystalline diamond epitaxial thin layer on the ground surface of the n-type monocrystalline diamond by utilizing an MPCVD method, and then converting a hydrogen terminal on the surface of the thin layer into an oxygen terminal by means of acid pickling or ultraviolet ozone treatment to obtain a sample A; S3, putting the oxidized sample A into an annealing furnace for annealing so as to separate out phosphorus on the surface of the thin layer and reconstruct carbon atoms to obtain a high-conductivity diamond surface; and S4, plating the high-conductivity diamond surface with a metal electrode, and putting the high-conductivity diamond surface in an annealing furnace for annealing to form ohmic contact.

Description

technical field

[0001] The invention belongs to the technical field of electronic engineering, and in particular relates to a (100) orientation n-type single crystal diamond electrode ohmic contact forming method. Background technique

[0002] The n-type doping technology of diamond semiconductors limits its wide application in electronic devices. Japan's Material and Materials Research Institute used microwave plasma chemical vapor deposition (MPCVD) to successfully achieve n-type doping of diamond single crystal thin films on the surface of single crystal diamond (111) using phosphorus atoms. On this basis, they quickly carried out the application of diamond p-n junction and p-i-n junction diodes in the field of light-emitting devices and power electronic devices. However, the (111) plane has the problem of difficult mechanical polishing, and its metal / diamond contact interface properties and the photoelectric properties of the film are worse than that of the (100) plane....

Examples

Embodiment 1

[0031] Such as figure 1 , a (100) oriented n-type single crystal diamond electrode ohmic contact forming method, (100) oriented n-type single crystal diamond 1 is a self-supporting body material with a size of 3 × 3 × 0.3mm 3 , with a surface roughness of 1 nm. A 10nm-thick n-type diamond epitaxial thin layer 2 was epitaxially grown on its surface by MPCVD, and the growth conditions were: air pressure 100 Torr, gas flow rate 500 sccm, CH 4 / H 2 = 1%, PH 3 / CH 4 =0.1%, and the substrate temperature was 900°C. After the growth, the sample was placed in a 1:1 mixture of sulfuric acid and nitric acid, heated at 250 °C for 1 h to convert the surface hydrogen terminals into oxygen terminals, and annealed at 900 °C for 5 min to obtain a highly conductive diamond surface 3. Through photolithography, magnetron sputtering, and lift-off processes, W metal electrodes 4 are prepared on the high-conductivity diamond surface 3, and then annealed at 400° C. for 10 minutes in an argon atm...

Embodiment 2

[0033] Such as figure 1 , a (100) orientation n-type single crystal diamond electrode ohmic contact forming method, (100) orientation n-type single crystal diamond 1 is a single crystal thin film, the size is 10 × 10 × 0.001mm 3 , with a surface roughness of 2nm. The n-type diamond epitaxial thin layer 2 with a thickness of 100nm is epitaxially grown on its surface by MPCVD method, and the growth conditions are: air pressure 100Torr, gas flow rate 500sccm, CH 4 / H 2 = 1%, PH 3 / CH 4 = 1%, and the substrate temperature was 900°C. After the growth, the surface hydrogen terminals were transformed into oxygen terminals by ultraviolet ozone treatment, and annealed at 1100° C. for 5 minutes to obtain a highly conductive diamond surface 3 . Prepare Ti / Pt / Au metal electrodes 4 on the high-conductivity diamond surface 3 by photolithography, magnetron sputtering, and lift-off processes, and then anneal at 700° C. for 20 minutes in an argon atmosphere to form ohmic contacts.

Embodiment 3

[0035] Such as figure 1 , a (100) orientation n-type single crystal diamond electrode ohmic contact forming method, (100) orientation n-type single crystal diamond 1 is a self-supporting body material, the size is 5 × 5 × 0.5mm 3 , with a surface roughness of 2nm. A 50nm-thick n-type diamond epitaxial thin layer 2 was epitaxially grown on its surface by MPCVD method, and the growth conditions were: air pressure 100 Torr, gas flow rate 500 sccm, CH 4 / H 2 = 1%, PH 3 / CH 4=0.5%, and the substrate temperature was 900°C. After the growth, the sample was placed in a 1:1 mixture of sulfuric acid and nitric acid, heated at 250 °C for 1 h to convert the surface hydrogen terminals into oxygen terminals, and annealed at 1000 °C for 10 min to obtain a highly conductive diamond surface 3. Prepare Ti / Au metal electrodes 4 on the highly conductive diamond surface 3 by photolithography, magnetron sputtering, and lift-off processes, and then anneal at 550°C for 20 minutes in an argon atm...

technical field

[0001] The invention belongs to the technical field of electronic engineering, and in particular relates to a (100) orientation n-type single crystal diamond electrode ohmic contact forming method. Background technique

[0002] The n-type doping technology of diamond semiconductors limits its wide application in electronic devices. Japan's Material and Materials Research Institute used microwave plasma chemical vapor deposition (MPCVD) to successfully achieve n-type doping of diamond single crystal thin films on the surface of single crystal diamond (111) using phosphorus atoms. On this basis, they quickly carried out the application of diamond p-n junction and p-i-n junction diodes in the field of light-emitting devices and power electronic devices. However, the (111) plane has the problem of difficult mechanical polishing, and its metal / diamond contact interface properties and the photoelectric properties of the film are worse than that of the (100) plane....

Examples

Embodiment 1

[0031] Such as figure 1 , a (100) oriented n-type single crystal diamond electrode ohmic contact forming method, (100) oriented n-type single crystal diamond 1 is a self-supporting body material with a size of 3 × 3 × 0.3mm 3 , with a surface roughness of 1 nm. A 10nm-thick n-type diamond epitaxial thin layer 2 was epitaxially grown on its surface by MPCVD, and the growth conditions were: air pressure 100 Torr, gas flow rate 500 sccm, CH 4 / H 2 = 1%, PH 3 / CH 4 =0.1%, and the substrate temperature was 900°C. After the growth, the sample was placed in a 1:1 mixture of sulfuric acid and nitric acid, heated at 250 °C for 1 h to convert the surface hydrogen terminals into oxygen terminals, and annealed at 900 °C for 5 min to obtain a highly conductive diamond surface 3. Through photolithography, magnetron sputtering, and lift-off processes, W metal electrodes 4 are prepared on the high-conductivity diamond surface 3, and then annealed at 400° C. for 10 minutes in an argon atm...

Embodiment 2

[0033] Such as figure 1 , a (100) orientation n-type single crystal diamond electrode ohmic contact forming method, (100) orientation n-type single crystal diamond 1 is a single crystal thin film, the size is 10 × 10 × 0.001mm 3 , with a surface roughness of 2nm. The n-type diamond epitaxial thin layer 2 with a thickness of 100nm is epitaxially grown on its surface by MPCVD method, and the growth conditions are: air pressure 100Torr, gas flow rate 500sccm, CH 4 / H 2 = 1%, PH 3 / CH 4 = 1%, and the substrate temperature was 900°C. After the growth, the surface hydrogen terminals were transformed into oxygen terminals by ultraviolet ozone treatment, and annealed at 1100° C. for 5 minutes to obtain a highly conductive diamond surface 3 . Prepare Ti / Pt / Au metal electrodes 4 on the high-conductivity diamond surface 3 by photolithography, magnetron sputtering, and lift-off processes, and then anneal at 700° C. for 20 minutes in an argon atmosphere to form ohmic contacts.

Embodiment 3

[0035] Such as figure 1 , a (100) orientation n-type single crystal diamond electrode ohmic contact forming method, (100) orientation n-type single crystal diamond 1 is a self-supporting body material, the size is 5 × 5 × 0.5mm 3 , with a surface roughness of 2nm. A 50nm-thick n-type diamond epitaxial thin layer 2 was epitaxially grown on its surface by MPCVD method, and the growth conditions were: air pressure 100 Torr, gas flow rate 500 sccm, CH 4 / H 2 = 1%, PH 3 / CH 4=0.5%, and the substrate temperature was 900°C. After the growth, the sample was placed in a 1:1 mixture of sulfuric acid and nitric acid, heated at 250 °C for 1 h to convert the surface hydrogen terminals into oxygen terminals, and annealed at 1000 °C for 10 min to obtain a highly conductive diamond surface 3. Prepare Ti / Au metal electrodes 4 on the highly conductive diamond surface 3 by photolithography, magnetron sputtering, and lift-off processes, and then anneal at 550°C for 20 minutes in an argon atm...

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