steering hot carriers away from the sensitive gate oxide and channel regions as a result this structure improves reliability and avalanche ruggedness without sacrificing cell density as much as a deeper heavy body junction this abrupt junction can be achieved by the double doping process that will be described below or by other processes for forming abrupt junctions many of which are known in the semiconductor field lastly referring to fig2 the cell array is surrounded by a field termination junction 40 which increases the breakdown voltage of the device and thaws avalanche current away from the cell array to the periphery of the die field termination junction 40 is a deep p well preferably from about 1 to 3 u03bcm deep at its deepest point that is deeper than the p heavy body regions 34 in order to reduce the electric field caused by the junction curvature a preferred process for making the above described transistors is shown as a flow diagram in fig3 and the individual steps are shown schematically in fig4 4 k it is noted that some steps that are conventional or do not require illustration are described below but not shown in fig4 4 k as indicated by the arrows in fig3 and as will be discussed below the order of the steps shown in fig4 4 k can be varied moreover some of the steps shown in fig4 4 k are optional as will be discussed a semiconductor substrate is initially provided preferably the substrate is a n si substrate having a standard.