City University of Hong Kong

Wen-Jun Zhang

Shuit-Tong Lee

Igor Bello

Yat Ming Chong

You-Sheng Zou

Kar Man Leung

Kwok Leung Ma

Qing Ye

A conical structure of cubic Boron Nitride (cBN) is formed on a diamond layered substrate. A method of forming the cBN structure includes steps of (a) forming diamond nuclei on a substrate, (b) growing a layer of diamond film on the substrate, (c) depositing a cBN film on said diamond layer, (d) pre-depositing nanoscale etching masks on the cBN film, and (e) etching the deposited cBN film. In particular, though not exclusively, the cubic Boron Nitride structure has great potential applications in probe analytical and testing techniques including scanning probe microscopy (SPM) and nanoindentation, nanomechanics and nanomachining in progressing microelectromechanical system (MEMS) and nanoelectyromechanical system (NEMS) devices, field electron emission, vacuum microelectronic devices, sensors and different electrode systems including those used in electrochemistry.

Method of fabrication of cubic boron nitride conical microstructures

A surface acoustic wave (SAW) device which is made of cBN/diamond composite structures and the fabrication method are disclosed. In the SAW device based on cubic boron nitride and diamond composite structures, the diamond hard layer includes randomly-oriented polycrystalline diamond (poly-D), oriented (heteroepitaxial) diamond, single-crystal diamond wafers and nanocrystalline diamond (nano-D) films. The cBN film with a sound velocity close to that of diamond serves as the piezoelectric layer, which was directly deposited on diamond hard layer without any soft sp-BN incubation layer by ion assisted physical vapor deposition (PVD) and plasma-enhanced (or ion assisted) chemical vapor deposition (PECVD). Due to the high sound velocity and the low velocity dispersion between the cBN and diamond layered materials, the present SAW device based on cubic boron nitride and diamond composite structures can improve the device performance and operate at ultra-high frequency range.

Surface acoustic wave (SAW) devices based on cubic boron nitride/diamond composite structures

Growing community of inventors

Hong Kong, China

Wen-Jun Zhang