CRYSTAL GROWTH ELSEVIER Journal of Crystal Growth 145 (1994) 630—635 ______________________ Modelling of growth in a 5 x 3 inch multiwafer metalorganic vapour phase epitaxy reactor T. Bergunde a,*, F. Durst b L. Kadinski b Yu.N. Makarov 13 M. Schafer b, M. Weyers a a Ferdinand-B raun-Institut für Hochstfrequenztechnik, Rudower Chaussee 5, D-12489 Berlin, Germany b Lehrstuhlfür Strömungsmechanik, University of Erlangen—Nürnberg, Cauerstrasse 4, D-91058 Erlangen, Germany Abstract A detailed theoretical study of the growth of GaAs and AIGaAs in a multiwafer PLANET reactor has been performed and combined with experimental verification. The effects of variations in temperature profile, flow rate and flow distribution have been studied and basic trends have been identified. Parasitic depositions on the reactor ceiling have been studied and their profile has been understood. Based on the investigations, thickness homogeneity was improved to better than ± 1% on 3 inch wafers. 1. Introduction [2—4]. The original design for multiwafer growth on 2 inch wafers has been upscaled to 4 inches Successful production of high electron mobility [51. Design and application of this reactor type transistor (HEMT) structure wafers by metalor- have been supported by a number of theoretical ganic vapour phase epitaxy (MOVPE) requires studies based on numerical simulations [3,5,6]. the simultaneous optimization of homogeneity However, the variety of calculated diagrams has and layer quality of each of the constitutent ma- been verified by only few experimental data. Also terials AlGaAs, GaAs and InGaAs. Additionally, the errors in the thickness data often are in the the interface quality has to be optimized. In a range of the desired homogeneity of ± 1%, mak- multiwafer reactor like the PLANET reactor this ing a comparison of experimental and theoretical task is further complicated by a number of reac- data difficult [3]. Additionally, essential reactor tor-specific control parameters making experi- parameters like susceptor and ceiling tempera- mental optimization a time consuming procedure. ture or inlet geometry have not yet been charac- The PLANET reactor type has been introduced terized in their influence on transport properties in 1988 [1] and has since then been successfully and the growth process. Gas phase reactions and applied to the growth of a variety of structures parasitic depositions have generally been ne- glected in the models and investigations until now. _______ When starting up an Aix-2000 PLANET reac- * Corresponding author. tor, we noticed that some of the trends predicted 0022-0248/94/$07.00 © 1994 Elsevier Science B.V. All rights reserved SSDI 0022-0248(94)00370-2