Xidian University

Hui Guo

Yuming Zhang

Keji Zhang

Pengfei Deng

Tianmin Lei

Hao Yuan

Chao Han

Yujuan Zhang

Yanqiang Shi

Yanfei Hu

Jiabo Liang

Yanjing He

Yuting Ji

Fengqi Zhang

A SiC ohmic contact preparation method is provided and includes: selecting a SiC substrate; preparing a graphene/SiC structure by forming a graphene on a Si-face of the SiC substrate; depositing an Au film on the graphene of the graphene/SiC structure; forming a first transfer electrode pattern on the Au film by a first photolithography; etching the Au film uncovered by the first transfer electrode pattern through a wet etching; etching the graphene uncovered by the Au film through a plasma etching after the wet etching; forming a second transfer electrode pattern on the SiC substrate by a second photolithography; depositing an Au material on the Au film exposed by the second transfer electrode pattern and forming an Au electrode and then annealing. The graphene reduces potential barrier associated with the SiC interface, specific contact resistance of ohmic contact reaches the order of 10˜10Ω·cm, and the method has high repeatability.

Method for preparating SiC ohmic contact with low specific contact resistivity

Disclosed is a method for preparing structured graphene on a SiC substrate on the basis of Clreaction, the procedures are as follows: firstly, performing standard cleaning to a SiC sample chip; depositing a layer of SiOon the surface of the SiC sample chip and engraving a figure window on the SiOlayer; then arranging the windowed sample chip in a quartz tube, introducing a mixed gas of Ar and Clinto the quartz tube, reacting the bare SiC with Clfor 3-8 min at 700-1100&#xb0; C. to generate a carbon film; arranging the generated carbon film in Ar gas, annealing for 10-30 min at 1000-1200&#xb0; C. to generate the structured graphene on the window on the carbon film. The method is simple and safe; the generated structured graphene has a smooth surface and low porosity and can be used for making microelectronic devices.

[object Object]

A layer I vanadium-doped PIN-type nuclear battery, including from top to bottom a radioisotope source layer(), a p-type ohm contact electrode(), a SiOpassivation layer(), a SiOcompact insulation layer(), a p-type SiC epitaxial layer(), an n-type SiC epitaxial layer(), an n-type SiC substrate() and an n-type ohm contact electrode(). The doping density of the p-type SiC epitaxial layer() is 1&#xd7;10to 5&#xd7;10cm, the doping density of the n-type SiC substrate() is 1&#xd7;10to 7&#xd7;10cm. The n-type SiC epitaxial layer() is a low-doped layer I formed by injecting vanadium ions, with the doping density thereof being 1&#xd7;10to 5&#xd7;10cm. Also provided is a preparation method for a layer I vanadium-doped PIN-type nuclear battery. The present invention solves the problem that the doping density of layer I of the exiting SiC PIN-type nuclear battery is high.

I-layer vanadium-doped PIN type nuclear battery and the preparation process thereof

Provided is a process for preparing graphene on a SiC substrate, based on metal film-assisted annealing, comprising the following steps: subjecting a SiC substrate to a standard cleaning process; placing the cleaned SiC substrate into a quartz tube and heating the quartz tube up to a temperature of 750 to 1150&#xb0; C.; introducing CClvapor into the quartz tube to react with SiC for a period of 20 to 100 minutes so as to generate a double-layered carbon film, wherein the CClvapor is carried by Ar gas; forming a metal film with a thickness of 350 to 600 nm on a Si substrate by electron beam deposition; placing the obtained double-layered carbon film sample onto the metal film; subsequently annealing them in an Ar atmosphere at a temperature of 900 to 1100&#xb0; C. for 10-30 minutes so as to reconstitute the double-layered carbon film into double-layered graphene; and removing the metal film from the double-layered graphene, thereby obtaining double-layered graphene. Also provided is double-layered graphene prepared by said process.

Process for preparing graphene on a SiC substrate based on metal film-assisted annealing

A method for preparing graphene by reaction with Clbased on annealing with assistant metal film is provided, comprising the following steps: applying normal wash to a Si-substrate, then putting the Si-substrate into a reaction chamber of a CVD system and evacuating, rising the temperature to 950&#xb0; C.-1150&#xb0; C. gradually, supplying CHand carbonizing the Si-substrate for 3-10 min; rising the temperature to 1150&#xb0; C.-1350&#xb0; C. rapidly, supplying CHand SiH, growing a 3C&#x2014;SiC hetero-epitaxial film on the carbonized layer, and then reducing the temperature to ambient temperature under the protection of Hgradually, introducing the grown sample wafer of 3C&#x2014;SiC into a quartz tube, heating to 700-1100&#xb0; C., supplying mixed gas of Ar and Cl, and reacting Clwith 3C&#x2014;SiC to generate a carbon film, applying the sample wafer of carbon film on a metal film, annealing at 900&#xb0; C.-1100&#xb0; C. for 10-30 min to reconstruct the carbon film into graphene; and taking out of the metal film from the sample wafer of graphene to obtain large area graphene. The graphene obtained by the method has large area, smooth surface, good continuity, and low porosity; and the product can be used to seal gas and liquid.

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Xi'an, China

Hui Guo