Selective area processing of InGaAsP

Abstract

The electrical activation characteristics of Si/sup +/ and Be/sup +/ ions implanted into InGaAsP (/spl lambda/=1-3 /spl mu/m) grown lattice-matched to InP by metalorganic molecular beam epitaxy were studied as a function of ion dose (5/spl times/10/sup 12/-5/spl times/10/sup 14/ cm/sup -2/), annealing time (3-60 sec) and annealing temperature (575-750/spl deg/C). Maximum doping concentrations of /spl sim/2/spl times/10/sup 19/ cm/sup -3/ were obtained for both Si/sup +/ and Be/sup +/, with activation energies for electrical activation of 0.58 eV and 0.39 eV, respectively. Multiple energy F/sup +/ or H/sup +/ implants can be used to produce high resistance layers for isolation purposes - maximum sheet resistances of /spl sim/8/spl times/10/sup 6/ /spl Omega/spl square/ or /spl sim/10/sup 6/ /spl Omega/spl square/ for initially p/sup +/ or n/sup +/InGaAsP, respectively, were obtained for F/sup +/ implants followed by annealing near 450/spl deg/C. Smooth, anisotropic dry etching of the InGaAsP is obtained with electron cyclotron resonance CH/sub 4H/sub 2Ar discharges at low DC biases. The etch rates are the same for both n/sup +/ and p/sup +/ quaternary layers and are independent of the doping level.<>