Abstract: A pattern control system and method for a charged particle beam such as a focused ion beam (FIB) (20) or electron beam writes beam patterns on a pixel-by-pixel (56) basis. Respective dwell times and beam blanking states are specified for each separate pixel location (56), enabling the creation of arbitrary patterns and various implantation gradients. Pixel commands are generated by a central processing unit (CPU) (104), which can be relieved by hardware pattern generators (FIG. 10) for frequently used patterns. The system also includes improvements in stigmation control, fiducial mark recognition and the reconciliation of the beam and target coordinate systems.

Abstract: A two-terminal active network which simulates a low noise-temperature resistor is disclosed. In a preferred embodiment, a pair of operational amplifiers, each connected in the manner of a "current pump," comprises the active elements of the network. A resistive voltage divider network provides both positive and negative feedback to the operational amplifiers. Simulated resistors can be obtained with a wide range of equivalent resistance values and effective noise temperatures.