Growth and characterization of phosphorous doped {111} homoepitaxial diamond thin films

Abstract

An n-type semiconducting diamond thin film was obtained by microwave enhanced plasma chemical vapor deposition using phosphine (PH3) as a dopant source. A homoepitaxial diamond thin film with a thickness of about 300 nm was grown on the {111} surface of a type Ib diamond with a variety of dopant concentrations. Over a wide range of dopant concentrations (PH3/CH4: 1000–20 000 ppm), the n-type conduction was confirmed by Hall-effect measurements. The activation energy of carriers was 0.43 eV. The Hall mobility of about 23 cm2/V s has been obtained at around 500 K for the 1000 ppm sample. No significant increase of hydrogen has been observed by secondary-ion-mass-spectroscopy analysis for the phosphorous doped layers.

Incorporation of Large Impurity Atoms into the Diamond Crystal Lattice: EPR of Split-Vacancy Defects in Diamond

“…The authors stated that the new spectrum had the HFS from one phosphorus atom and one nitrogen atom; however, no information on the parameters was provided [39]. Finally, in the late 90s, phosphorus doped (111) homoepitaxial diamond layers with n-type conductivity were obtained [40,41].…”

Multiple phosphorus chemical sites in heavily phosphorus-doped diamond

“…Nitrogen gives a deep donor level with an activation energy of 1.7 eV. 2,3 This means that its application as a device is difficult because of the nearly zero excitation of electrons into the conduction band at room temperature. P gives a shallower donor level of 0.6 eV from the conduction band minimum.…”

“…4,5 This is the reason for the success of making controlled carrier concentration in n-type diamond films by light P-doping. 3 One of the possible research directions of P-doped diamond is to obtain metallic samples because of the possible occurrence of superconductivity as in heavily B-doped diamond. 6,7 Recently, heavily P-doped diamond with P concentration ͑n p ͒ as high as ϳ10 20 cm −3 has been obtained by microwave plasma assisted CVD ͑MPCVD͒.…”

“…8 The sample, whose thickness is 2 m, was homoepitaxially grown on synthetic Ib diamond ͑111͒ substrate with dimensions of 2 ϫ 2 ϫ 0.5 mm 3 . n P of 1 ϫ 10 20 cm −3 ͑0.06 at.…”

Doping and cluster formation in diamond

“…Both nitrogen (N) and phosphorous (P) are rather problematic. [7][8][9] In particular, N (one more valence electron than C) does not contribute to the conduction band but leads to the formation of a lone electron pair on N and a dangling bond on one of its nearest neighbour C atoms. Experimentally, it has been determined that the unpaired electron is localized more on a C nearest neighbour atom than on the N donor atom.…”