Implant isolation of both n-type InP and InGaAs by iron irradiation: Effect of post-implant annealing temperature

Abstract

Abstract1 MeV Fe' was implanted into n-type InP and InGaAs layers at different substrate temperatures, -196'C, room temperature (RT), 100°C and 2OO0C to obtain highresistivity regions. The sheet resistivity of the InP and InGaAs epilayers grown on semiinsulating (SI) InP substrates was measured as a function of substrate temperature and post-implantation annealing temperature (100 -SOO' C). For InP, a maximum sheet resistivity of -lx107 W O was achieved for samples implanted at -196OC, RT and 100°C after annealing at 400'C. For InGaAs samples, a maximum sheet resistivity of M O 7 and 2 . 3~1 0~ WO is obtained for -196'C and RT implants respectively after annealing at 650'C for 60s. In both InP and InGaAs, the isolated regions exhibit good stability to heat treatment up to 5OO' C for all cases irrespective of the irradiation temperature. The iron depth profile obtained by secondary ion mass spectrometry (SIMS) shows that iron does not diffuse up to an annealing temperature of 550'C in both InP and InGaAs for all implantation temperatures. These results are novel since high sheet resistivity (-5x106 N O ) is obtained in both InP and InGaAs samples implanted at -196' and RT, and annealed at 400'C. These data demonstrate the potential usefulness of iron implantation for isolation of InPDnGaAs based devices.

Critical process temperatures for resistive InGaAsP/InP heterostructures heavily implanted by Fe or Ga ions

“…Comedi et al remarked that amorphization of InGaAsP led to high resistivity and stability after annealing/recrystallization [8]. Similar behavior was also noted in the case of high fluence Fe implantation studies in In 0.53 Ga 0.47 As [6,9,10]. These observations motivated our use of cold Fe-implantation, done at 83 K, to produce an ultrafast photoconductive material working at 1550 nm which is based instead on an InGaAsP alloy with E g = 0.79 eV.…”

“…Part of that improvement could be linked to a lower T c for In 0.53 Ga 0.47 As, based on data available on InAs and GaAs [25]. Finally, regarding Fe implantation done at 83 K, experimental resistivity improvement factors are smaller, about 4 and 10 [6,9]. In this case, T impl is well below T c for both alloys.…”

Fabrication of high resistivity cold-implanted InGaAsP photoconductors for efficient pulsed terahertz devices

“…SRIM software simulations predicted 6.5 atomic displacements per atom (using 10 eV as the displacement energy for In, Ga, As, and P atoms). According to Too et al [25], Marcinkevičius et al [26] and Subramaniam et al [27], the implantation temperature can also affect significantly the electrical properties of Fe-implanted In 0.53 Ga 0.47 As at high fluences. The InGaAsP samples were implanted at 83 K for that very reason.…”

“…Either shallow donor defects are forming, such as As or P antisites [22], or donor impurities intrinsic to the material are re-activated. Other possible mechanisms might be related to the dissociation of Fe defect complexes, or related to the in-diffusion of interface contaminants such as C or Si, or else the out-diffusion of Fe at high annealing temperatures, as it typically does [25]. Detailed analysis of impurity depth profiles with secondary ion mass spectrometry and advanced capacitance-voltage measurements would be required for a proper assignment.…”