Piezoresistivity of Polycrystalline Diamond Films
ABSTRACTPolycrystalline diamond film (PDF) is known for its high power, high temperature, and radiation hard potential. The interest in piezoresistivity of PDF is that it is a candidate for high temperature sensing (e.g., pressure sensor).Piezoresistivity measurements were taken of boron-doped PDF grown by microwave-plasma chemical vapor deposition(CVD). Three substrates, silicon, aluminum nitride and tungsten were used. Films were detached from these substrates, then attached to a ceramic substrate. The piezoresistivity varies, dependent on the original host substrate. For example, at room temperature, the PDF film from tungsten has a greater gauge factor, around 75. The carrier activation energy of this film, determined from log R(l/T), was nominally 0.25eV.Combining thick film technology and CVD processes, patterned B-doped PDF has been achieved monolithically on A1N substrates. The characteristics of this configuration is being investigated and will be presented.