Thermal expansion of polycrystalline diamond produced by chemical vapor deposition

Abstract

The in-plane thermal expansion of thick freestanding polycrystalline diamond films produced by hot filament chemical vapor deposition was measured by dilatometry. Measurements were obtained from two different diamond wafers over a temperature range of −200 to +800 °C. Within experimental error of the measurements, values agree with those reported for natural single-crystal diamond. Quantification of the thermal expansion of chemically vapor deposited (CVD) diamond is important for determining thermal stresses which will be encountered during deposition of diamond on various substrate materials and during use of diamond in various applications.

Modelling wafer bow in silicon–polycrystalline CVD diamond substrates for GaN-based devices

“…The CTE, , of both silicon and diamond is isotropic owing to its crystallographic structure, such that x = y = z . [15,16] …”

Thermal expansion coefficient of hydrogenated amorphous carbon

“…Chemical vapor deposited diamond ͑CVD diamond͒ has a CTE very close to that of natural diamond. 12 The CTE of a-C:H approaches that of diamond as the sp 3 concentration increases, therefore we can also expect that the CTEs of ta-C and ta-C:H to be close to that of diamond.…”

Crystallographic anisotropy of wear on a polycrystalline diamond surface

“…Polycrystalline CVD diamond films can be deposited on a variety of substrates over large (100's of cm 2 ) areas, and the thermal and mechanical properties of these films are similar to those of natural diamond. [1][2][3][4][5][6][7][8][9][10][11] .…”

“…[1][2][3][4][5][6][7][8][9][10][11] . One of the main obstacles to many potential diamond applications is the roughness of the as-deposited films.…”