Active diamond electronics electronic device

Electronic. Diamonds have been used as thermistors and radiation detectors, but inhomogeneities within the crystals have seriously limited these appHcations where diamond is an active device. This situation is rapidly changing with the availabiHty of mote perfect stones of controUed chemistry from modem synthesis methods. The defect stmcture also affects thermal conductivity, but cost and size are more serious limitations on the use of diamond as a heat sink material for electronic devices. 

The present author has pointed out on a number of occasions (19-22) that the early enthusiasm for the production of active electronic devices and optoelectronic devices based on diamond was misplaced. At the time of writing the present chapter many laboratories set up to exploit this multibillion dollar market are closing down or turning their attention to other materials. The past decade of intense activity on diamond has revealed many interesting characteristics of this unique material, some of which are recorded in this chapter, but sadly all the... 

Landstrass and Ravi first reported the p type surface conductivity of diamond [80, 81]. Gi et al. [82, 83] showed that the surface conductivity increased when exposed to acidic vapors and decreased when exposed to basic vapors. This near-surface p type conductivity is characterized by a high carrier sheet density of about 10 cm 2 from 150 400 K, an activation energy of less than 50 meV, and a low density of surface states [78, 84-86]. These attributes have led to its application in electronic devices such as field effect transistors [84-86]. 

Activation and conductivity at room temperature are problems that can be addressed by the incorporation of other electronic structures that increase carrier transport. Crystal morphology is an important parameter in the boron doping process to determine uncompensated acceptors (Aa-Ad) for different crystal facets as a function of doping concentration. The temperature coefficient of resistance for a CVD diamond film can be changed by boron doping. As conductivity depends on the crystal phase, the combined electromechanical properties can be exploited in sensor applications both for resistive temperature detectors and for pressure transdu-cers. " As electrical conductivity is related linearly with boron concentration, a better-controlled process may allow for the development of better semiconductor devices improving crystal quality and operating limits. ... 

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