Phosphorus-vacancy-related deep levels in GaInP layers

Abstract

Deep levels in lattice-matched Ga0.51In0.49P/GaAs heterostructure have been investigated by thermal-electric effect spectroscopy (TEES) and temperature-dependent conductivity measurements. Four samples were grown by molecular-beam epitaxy with various phosphorus (P2) beam-equivalent pressures (BEP) of 0.125, 0.5, 2, and 4×10−4 Torr. A phosphorus vacancy (VP) -related deep level, an electron trap, was observed located at EC−0.28±0.02 eV. This trap dominated the conduction-band conduction at T≳220 K and was responsible for the variable-range hopping conduction when T<220 K. Its concentration decreased with the increasing phosphorous BEP. Successive rapid thermal annealing showed that its concentration increased with the increasing annealing temperature. Another electron trap at EC−0.51 eV was also observed only in samples with P2 BEP less than 2×10−4 Torr. Its capture cross section was 4.5×10−15 cm2. This trap is attributed to VP-related complexes.

Cation and anion vacancies in proton irradiated GaInP

“…27 DLTS studies have reached a variety of different conclusions regarding the origin of the low temperature peak in GaInP, such as cation vacancies ͑SSMBE material 28 ͒, a dopant related DX center ͑MBE material 29,30 ͒, interstitial phosphorus ͑liquid phase epitaxial material 31 ͒ and phosphorus vacancies ͑MBE͒. 32 The observations of Kwon et al 33 showed that the emission rate of the N1 peak is affected by the type of dopant ͑S, Se, and Te were tested͒ suggesting it to be a complex. To investigate this further, the rate of increase of the N1 peak was measured using the same method as in our previous work on N3 3 .…”

Hydrogenation effect of InGaP grown on GaAs by molecular beam epitaxy

“…The concentration of P1 and P2 in undoped InGaP decreased with increasing P2 BEP, suggesting that these traps may be associated with the crystal defects in the P deficient lattice sites such as the phosphorus vacancies(V,). Also, the origin of P3 and P4 signals were attributed to phosphorus vacancies V, andior a transformed defect from V, such as a Gap or In, antisite [5]. After hydrogenation at 200 "C for 2 h, the relative intensities of all traps decreased in about 10 times and only two signals corresponding to P3 and P4 traps around 180 K and 280 K remained as main defects.…”

Electron states at point defects in non-uniform semiconductor alloys

“…These states in alloys have been widely studied during recent years (see e.g. [1][2][3][4][5] and references therein) for the cases of Coulombic and short-range potential defects. The latter case is typical for states localized on structure imperfections or on substitutional impurities.…”