n-type phosphorus-doped polycrystalline diamond on silicon substrates

Slimane Ghodbane (1) , Franck Omnès (1) , Etienne Bustarret (1) , Céline Tavares (1) , François Jomard (2)

1 NEEL - SC2G - Semi-conducteurs à large bande interdite
2 GEMAC - Groupe d'Etude de la Matière Condensée

The microwave plasma-assisted deposition of reproducible and homogeneously n-type phosphorus-doped polycrystalline (microcrystalline) diamond films on silicon substrates is described. The phosphorus incorporation is obtained by adding gaseous phosphine (PH3) to the gas mixture during growth. The low CH4/H2 ratio (0.15%) and the use of the same growth parameters as for homoepitaxial {111} films, led to a good crystalline quality of the continuous polycrystalline diamond layers, confirmed by SEM images and Raman spectroscopy measurements. Secondary-ion mass spectrometry (SIMS) analysis measured a phosphorus concentration [P] of at least 7×1017 cm−3. Cathodoluminescence spectroscopy in our P-doped polycrystalline films shows a phosphorus bound exciton (BETO P) peak between 5.142 and 5.181 eV. Cathodoluminescence and Raman-effect spectroscopy confirmed the improvement of the crystalline quality of our films as well as a decrease in the intensity of the internal strain when the grain size was decreased. Cathodoluminescence imaging and SIMS depth profile of phosphorus demonstrated a very good homogeneity of phosphorus incorporation in the films.

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Matériaux

Slimane Ghodbane, Franck Omnès, Etienne Bustarret, Céline Tavares, François Jomard. n-type phosphorus-doped polycrystalline diamond on silicon substrates. Diamond and Related Materials, 2008, 17, pp.1324. ⟨10.1016/j.diamond.2008.01.090⟩. ⟨hal-00761492⟩