Hydrogen passivation of acceptors in p-InP

Abstract

The problem of hydrogenation ofInP without surface degradation has been surmounted by exposure of the InP surface to a hydrogen plasma through a thin SiN); (H) cap layer. This layer is H permeable at the hydrogenation temperature of 250 °e, but P or PH J impermeable thus minimizing PH 3 10ss and the attendant In droplet formation. In contrast to our results for this type of plasma exposure of GaAs, we find that shallow acceptors in InP are heavily passivated, whereas shallow donors are only very weakly affected. For exampie,p r--InP(Zn) of 3 X 10 18 cm-3 has its residual hole concentration reduced to <;3 X 10 14 cm-3 over a depth of 1.3 pm by a 250 ·C, 0.5 h deuteration. The presence of acceptors impedes H (or D) indiffusion, as indicated by D diffusion under the same conditions occurring to depths of 18 and 35 pm inp-InP (Zn, 2x 10 16 cm--3 ) and n-InP (5 or Sn), respectively. Annealing for 1 min at 350°C causes the acceptor passivation to be lost and the hole concentration to be returned to its prehydrogenation level, indicating that the passivation has similar thermal stability to that of acceptors in GaAs, but lower than that of donors.

Multiwafer zinc diffusion in an OMVPE reactor

“…In agreement with earlier studies using sealed ampoule diffusion [6] and OMVPE diffusion [3], the maximum hole concentration after diffusion but before annealing is between 20-50% of the maximum Zn concentration; this increases to 30-75% after a post-diffusion RTA using the annealing conditions detailed above. Two mechanisms have been proposed to account for the lower hole concentration compared to the total Zn concentration: passivation of the Zn by atomic hydrogen [7,8], or compensation of the substitutional Zn by an interstitial donor [6,9]. An increase in hole concentration after annealing is consistent with either mechanism.…”

Proposal for an etching mechanism of InP in CH4-H2 mixtures based on plasma diagnostics and surface analysis

“…In addition the In removal rate depends mostly on the flux of active neutral species, such as CH 3 , and depends only weakly on the flux of ionic species. In contrast the In atom surface density is equal to that of the bulk material N In ϭ5.8ϫ10 14 cm Ϫ2 .…”

Hydrogenation of HgCdTe epilayers on Si substrates using glow discharge plasma

“…Hydrogen has been used extensively 4,5,6 to influence the electrical properties of Si and III-V materials as well as a number of heterostructure systems, such as GaAs/Si, 7 GaAs/InP, 8 and epitaxial/homoepitaxial InP/InP. 9 Surprisingly, despite the improvements found for these materials' systems, there has been very little work reported on hydrogen passivation in HgCdTe. This has recently led us, as well as others, 10 to investigate this possibility.…”