Korea Institute of Science and Technology

Young-Joon Baik

Kwang Yong Eun

Wook-Seong Lee

Jae-Kap Lee

Ki-Woong Chae

Joo-Yong Lee

Jeung-Hyun Jeong

Dong-Ryul Jeon

In the method for depositing a material in the absence of a positive column, a discharge is generated between a cathode and an anode disposed to face each other in a reaction chamber by applying a DC voltage therebetween, and introducing reaction gas into the reaction chamber, thereby depositing a material on a substrate mounted on the anode and serving as a part of the anode, wherein the deposition of the material on the substrate is performed under a state that a cathode glow and an anode glow exist in a form of thin layers coating respectively the surfaces of the cathode and the substrate, while a positive column does not exist or is so small as to be negligible.

Method for DC plasma assisted chemical vapor deposition in the absence of a positive column

Disclosed are an apparatus and a method to synthesize powders typed diamond with the size between several tens nm to several &#x3bc;m in diameter using conventional CVD processes for deposition of diamond films. Gas phase nucleation has been induced on the boundary of plasmas, and as a result the spherical diamond powders accumulated have been obtained on circumferences of the normal substrate. With a modification of a substrate structure, a large area accumulation of the diamond powders of around 100 mm in diameter has been accomplished.

Apparatus and method for synthesizing spherical diamond powder by using chemical vapor deposition method

A diamond field emitter and a fabrication method thereof, in which a pretreatment is performed on a surface of an Si substrate in order that diamond nuclei are uniformly formed on the Si substrate during a diamond deposition, an oxide film such as an SiO film is deposited on the pretreated surface of the Si substrate and removed after an etching process so that diamond powder can be selectively remained during the etching process, thus the effect of the surface pretreatment of the Si substrate remains in the selected portion during the etching process, and it is also possible to uniformly deposit the diamond in said portion. According to the present invention, the diamond field emitter having excellent and uniform field emission characteristic can be manufactured because the field emission is easily achieved at a tip shaped field emission section, and, moreover, the diamond placed on an upper end portion of the tip increases electron emission effect.

Diamond field emitter and fabrication method thereof

A high curvature diamond field emitter tip fabrication method includes forming on a substrate a diamond film composed of square (100) phase-oriented facets and (111) phase-oriented facets distributed thereabout and columnar diamond particles having defect density differences between the diamond formed beneath the (100) and (111) diamond growth facets, and etching the diamond film using a oxygen-containing gas plasma. Further, the method includes forming on a substrate a diamond film composed of square (100) facets and (111) facets distributed thereabout and columnar diamond particles having defect density differences between the diamond formed beneath the (100) and (111) diamond growth facets, forming a supporting film on the diamond film, removing the substrate therefrom, and etching the diamond film using an oxygen-containing gas plasma after any one of the previously described steps.

High curvature diamond field emitter tip fabrication method

A fabrication method for a diamond-coated cemented carbide cutting tool includes electrolytically etching the surface of a cemented carbide cutting tool with a NaOH or KOH aqueous solution or chemically etching the surface of the cemented carbide cutting tool with a KMnO.sub.4 +KOH aqueous solution, and depositing a diamond film on the cemented carbide cutting tool. A stronger etching effect than by using a Murakami solution can be achieved, and no poisonous material is included in the etchant. In addition, disposal of the waste etchant is made simpler, and the adhesion between the diamond film coating and the cemented carbide cutting tool can be strengthened.

Fabrication method for diamond-coated cemented carbide cutting tool

An improved diamond film synthesizing apparatus and a method thereof using a direct current glow discharge plasma enhanced chemical vapor deposition advantageously providing a plurality of cathodes for forming a relatively large plasma size, which includes a reactor having an upper wall and a bottom wall; a plurality of spaced apart cathode holders half inserted into the upper wall of the reactor, arranged in a triangle when looking dowawardly over the head of the reactor; a plurality of cathode connecting rods, each of which is threadly connected to the cathode holders inside the reactor, respectively; a plurality of cathodes, each of which is threadly connected to the cathode connecting rods, respectively; an anode half inserted into the bottom wall of the reactor and having a substrate attached on the top thereof, whereby all the cathodes and the anodes are spaced apart inside the reactor by a predetermined distance; and a gas supplier connected to one side wall of the reactor having a circular gas supplying tube having a plurality of holes for injecting gas into the reactor. In addition, the diamond film synthesizing method using a direct current glow discharge plasma enhanced chemical vapor deposition comprises the methods of cutting off the heat transfer from a cathode to a cathode holder, thereby maintaining the temperature of a cathode to be within a predetermined range for a stable production of a plasma.

Diamond film synthesizing apparatus and method thereof using direct

There is disclosed a method for depositing a diamond film on a substrate which utilizes high density direct current glow discharge at a glow-arc transition region to form plasma between a cathode and an anode in a reactor, wherein the cathode maintains its temperature at a range of 2,100 to 2,300.degree. C. and is composed of a plurality of U-shaped filaments which are aligned parallel to one another to form an array and each of which is made by bending a conductive wire.

Growing community of inventors

Seoul, South Korea

Young-Joon Baik