Charge-based deep level transient spectroscopy of phosphorous-doped homoepitaxial diamond

Abstract

Articles you may be interested inPhotoinduced current transient spectroscopy of deep levels and transport mechanisms in iron-doped GaN thin films grown by low pressure-metalorganic vapor phase epitaxy Memory effects related to deep levels in metal-oxide-semiconductor structure with nanocrystalline Si A form of charge-based deep level transient spectroscopy ͑Q-DLTS͒ has been used to investigate electrically active defects within three phosphorus ͑P͒-doped, n-type, homoepitaxial diamond films, grown by the chemical vapor deposition technique, in an attempt to obtain a Q-DLTS signal related to the P-donor level itself. Four distinct peaks were observed in the Q-DLTS spectra, two of which could be fully analyzed. One of the other two peaks overlapped other structures in the measured spectra and so could not be fully characterized, while the fourth emerged at temperatures corresponding to the limit of the experimental system used. The two fully characterized peaks arose through the presence of levels with activation energies within the range 0.42-0.6 eV depending on the sample, contact scheme, and charging time used. One of these two peaks was only observed within two of the three samples. It occurred as a shoulder on the left-hand side of a more prominent and sharp Q-DLTS feature. Both of these Q-DLTS peaks are thought to originate from the P-related donor level in diamond, although their Q-DLTS activation energy values appeared to be scattered and most of the time significantly shallower than the value of 0.6 eV corresponding to the ground level of the P-related donor level. Such discrepancies are thought to arise essentially from retrapping effects, likely due to strong leakage currents at the metal/diamond interface. Improvements to the accuracy of the measurements made here is therefore expected if reliable, good quality, Schottky contacts to n-type diamond become obtainable.

Effect of doping on electronic states in B-doped polycrystalline CVD diamond films

“…Over the last two decades various activation energies and capture cross-sections have been reported for majority carrier traps in semiconducting diamond using capacitance transient spectroscopy techniques such as DLTS. [24][25][26] However, some of these data may have been misinterpreted due to the low resolution of the experimental measurements. Recently valuable information about defects in monocrystalline [27,28] and polycrystalline [3,29] diamond films have been obtained; however, the precise origin of these traps has still not been confirmed.…”

Theory of Jahn–Teller distortions of the P donor in diamond

“…Diamond of p-type is readily obtained using boron acceptors, but the natural n-type dopant, nitrogen, has a deep donor level at E c − 1.7 eV [1]. Despite theoretically being insoluble [2][3][4], doping with substitutional P (P s ) has proved the most reliable and best understood method of n-type doping of diamond, but with a rather deep donor level (∼E c − 0.6 eV [5][6][7]). Nevertheless, concentrations of P of 10 19 cm −3 have been achieved [8], and devices demonstrated [9][10][11][12].…”