REPLACEMENT OF HYDRIDES BY TBAS AND TBP FOR THE GROWTH OF VARIOUS III-V MATERIALS IN PRODUCTION SCALE MOVPE REACTORS

Besides the standard group V precursors AsH3 and PH3, so-called altern ative precursors like TBAs and TBP (tertiary-butyl-arsine and tertiary -butyl-phosphine) are more and more important in today's MOVPE process es. A lot of publications have demonstrated that these precursors can be successfully used for the growth of different III-V materials. In t his study we want to demonstrate that TBAs and TBP can be used as the group V precursor in a complete family of production scale reactors. I t is shown that these precursors can be used for the growth of InP-bas ed as well as for GaAs-based materials. The reactors that have been em ployed are medium scale reactors (AIX 200/4; 1 x 2 inch, 3 or 4 inch o r 3 x 2 inch capability) and large scale Planetary Reactors(R), in par ticular the AIX 2400 system(15 x 2 inch or 5 x 4 inch). Materials that have been grown are (Al)GaInP on GaAs and GaInAsP on InP. The lower c racking energy of these precursors compared to PH3 and AsH3 allows one to use lower growth temperatures and lower V/III ratios, particularly in combination with the high cracking efficiencies of the used reacto rs. For the growth of GaInAsP on InP, the consumption of TBP and TBAs is up to 8 times lower than using PH3 and AsH3. GaInP on GaAs could be grown with a V/III ratio as low as 25 in a Planetary Reactor(R). Good crystalline quality is demonstrated by DCXD (e.g. for GaInP: FWHM = 3 5 arcsec, substrate 32 arcsec). PL intensity and growth rate are not a ffected by using the alternative precursors. The compositional uniform ity is similar to layers grown with arsine and phosphine (e.g. 1.5 nm uniformity for GaInAsP (lambda = 1.5 mu m) on 2 inch; approximately I nm uniformity for GaInP) [1,2]. The purity of the grown layers depends mainly on the quality of the TBP and TBAs. Using high purity TBP, InP revealed background carrier concentration in the mid 10(14) cm(-3) re gime. Our investigation shows that TBP and TBAs can replace phosphine and arsine in state of the art MOVPE reactors. Both for single and mul ti-wafer production MOVPE reactors these compounds can be used success fully for the growth of the entire material spectrum in the Al-Ga-In-A s-P system.