Electrical properties of boron-doped diamond films grown by bias method.

 

S.Yugo,T.Tashiro and D.Saito

University of Electric-Communications

1-5-1,Chofugaoka,Chfu-shi,Tokyo ,Japan

(e-mail;yugo@diamond.crc.uec.ac.jp)

 

(Keywords; doped diamond films, bias method, electrical properties)

 

 

 The new method using the bias was proposed as a method for doping the impurity to the diamond.  Boron dope diamond film was produced in order to evaluate the effectiveness of this method, and the electrical characteristic was examined.  This new doping method is based on the principle which applies the negative bias in the diamond CVD equipment in installed electrode for the impurity.  The electrode for the impurity with the negative bias supplies the impurity in the plasma by ion-sputtering.  It is possible to promote diamond growth with the positive bias by the electron shower.  As the result, various impurity addition are enabled, while the diamond thin film is kept high-quality.  The boron-dope diamond film was produced by this method, and the electrical properties were examined.  First, by usual bias processing method, the diamond film for the insulation was produced on n-Si, and the boron-dope diamond film was produced on the substrate.  In the impurity source, Ti-B composite with the electrical conductivity was used, and the bias voltage changed from 0 to 300V.  As the result, the good boron-doped diamond film was obtained.  The electrical resistivity were about 10-2 Ω -cm, and the Hall mobility were about 200-1000 cm2/v.s.,  p-type were recobnized from Hall effect and Zeebeck effect.  The activation energy of the boron was about 0.3eV.  It is shown that the mobility of doped diamond films by this method are very high, and that the method of this impurity addition is effective for controlling electrical characteristic by the bias voltage.   

 

 

(Abstract1,ADC2001)