摘要:
The disclosure describes a method and structure to control the focussed ion beam induced deposition of material. The structure includes a focussed ion beam which is directed onto a target surface. The ion beam is deflected to locations on the target surface and is blanked and unblanked at desired intervals. The deflection and blanking are controlled by timing means in response to computer signals. A precursor gas is adsorbed into the target surface and the ion beam selectively decomposes the adsorbed gas along a desired shape to provide material deposition. The shape of the deposition is specified by a number of successive beam spots. The spots can be specified to overlap adjacent spots if desired for better edge resolution, but in general, the optimum yield is obtained without overlap. The dwell time for each spot is set to provide high net yield for the deposited material. The beam is stepped to each position in the shape and the deposition is repeated. Alternatively, the beam could be moved in sequential line scans either stepwise or continuously between spots, but spot by spot deflection allows better control of the feature shape. After completing all the spots in the pattern, the process is repeated until a film of material of the desired thickness is built up.
摘要:
A method for marking a mask set to insure minimum mismatch between the masks when they are assembled into a set. Each mask in the set is evaluated against a known fixed standard, identified and marked such that, when the set is assembled and utilized to produce an integrated circuit, minimum mismatch between each element in each mask in the set will be realized. This is achieved by aligning each mask to a known standard, forming an alignment indicator (24a, b; 77,78) in the form of a scale on each (first) mask, and forming a vernier scale (23a, b; 73, 74) on each subsequent mask. The vernier scale is marked to indicate which element must be aligned with an element on the previous mask to minimize mismatch.