GaN-based lamb-wave mass-sensors on silicon substrates

Abstract

Lamb-wave mass-sensors were fabricated with MOCVD-grown GaN-based thin films on silicon substrates. Crystalline GaN provides an alternative choice of material for fabricating Lamb-wave sensors. The advantageous properties of this material include high acoustic velocity, high chemical, mechanical and thermal stability, and the potential to integrate with a wide range of GaN-based devices such as high electron mobility transistor (HEMT) circuits, light emitting diodes (LED) and other photonic devices. We successfully developed GaNbased Lamb-wave mass-sensors in small size (membrane size of ~1mm × 1mm). The sensors showed good signal strength and mass sensitivity, comparable to other mass-sensors using conventional materials. This novel approach not only allows robust low-cost sensors to be fabricated, but also enables future integration with generic GaN-based devices on the same chip (i.e. lab-on-a-chip).I.

The influence of MBE and device structure on the electrical properties of GaAs HEMT biosensors

“…High electron mobility transistors attract a great deal of attention due to their high work cut-off frequency, low power consumption and low noise [6] . HEMT utilizes modulation doped heterojunction structure to separate the doped layer and conduct layer; this kind of structure possesses higher two dimension electron gas concentration and electron mobility [7,8] . Attributed to the wurtzite lattice structure, GaAs and GaN structure lack a symmetric center, so there is spontaneous polarization in their structure [9,10] .…”