CMOS devices constructed in substrates subject to highenergy implantation of boron for buried-layer fabrication are examined. The behavior of MOS transistors, junction leakage and break-down, material properties, and latchup susceptibility are studied in order to ascertain the extent of any deleterious effects produced by heavy implantation at energies in the megaelectronvolt range. It is seen that MOSFET transistor characteristics are virtually unaffected by such an implant. Surface-dependent parameters, such as mobility, transconductance, and threshold voltage were unchanged. Some variations in body effect, output resistance, well junction leakage, and bulk lifetime were noted. Latchup behavior was seen to improve with the incorporation of the buried layer, and the holding voltage increased as the well and implant depths decreased.