In situ cleaning of air-exposed InGaAs using trisdimethylaminoarsine for CBE regrowth aimed at optical devices

We report on the cleaning/regrowth of air-exposed Zn-doped InGaAs and carbo n-doped InGaAs films in a CBE chamber. Two cleaning procedures, one with tr isdimethylaminoarsine (TDMAAs) flux and the other with arsenic flux, are co mpared in terms of carrier profiles and interface residues. Pleating temper ature Drier to regrowth, i.e., cleaning temeprature T-c, is a key factor in both methods. TDMAAs cleaning provides flat carrier profiles in the T-c ra nge of 515-525 degrees C. while cleaning in arsenic ambience requires T-c o f 575 degrees C, SIMS analysis reveals that both residual oxides and hydroc arbons are significantly removed during TDMAAs cleaning but hydrocarbons ar e not removed under arsenic Bur. The TDMAAs cleaning/regrowth procedure was applied to form a heavily carbon-doped InGaAs layer on an MOCVD film with an optical modulator structure, It produces a modulator with an extinction ratio of 30 dB for 1.55 mu m wavelength light, (C) 1999 Elsevier Science B. V. All rights reserved.