FORMATION OF DELTA-DOPED, BURIED CONDUCTING LAYERS IN DIAMOND, BY HIGH-ENERGY, B-ION IMPLANTATION

The electrical properties of a deeply buried, boron-doped layer in typ e IIa diamond are reported. The layer is fabricated using mega-electro n-volt (MeV) B-ion implantation, followed by furnace annealing at 1450 degrees C. Electrical contact to the buried layer is made using laser -induced graphitization. The room temperature Hall mobility of the acc epters in the buried layer is 585 cm(2)/Vs, which is the highest value yet reported for ion-implanted diamond, with an acceptor concentratio n of (3.9 +/- 0.3) x 10(18) cm(-3), a compensation ratio of approximat ely 5%, and an activation energy of 0.354 +/- 0.006 eV. The temperatur e dependence of the mobility is very similar to that observed in natur al B-doped type IIb diamond. The cap overlying the implanted region, i s, following annealing, a high quality, highly insulating diamond, hen ce opening the possibility of realizing Field Effect Transistor (FET)- type devices in diamond. (C) 1998 Elsevier Science S.A. All rights res erved.