We investigate GalnP/GaAs high electron mobility transistor (HENIT) epitaxial structures grown in a production molecular beam epitaxy (MBE) system, with different interface commutation procedures. These structures have been designed to be very sensitive to the interface quality. They have been characterized by Hall measurements and photoluminescence. GaP- and GalnAs-type interfaces can be distinguished. Best mobility results occur for few second or even no growth interruption, demonstrating the very low As memory effect of this large MBE system. © 2005 Elsevier B.V. All rights reserved.