System for programmed drawing by particle bombardment

Claim 1

In an automatic device for forming programmed pattern by electron bombardment on a sample controlled by a data processing system, by forming upon the substrate an elementary rectangular image of a diaphragm, electronically controlled means for deflecting said image in a direction OX parallel to one of its sides, and scanning said sample line by line, mechanical displacing means in the OY direction perpendicular to OX a control electrode for modulating the beam intensity by all or nothing, a two stable state device controlling said electrode, an interface circuit controlled by said data processing system comprising a buffer memory and an assembly of memories, an improvement in said interface circuit consisting of a clock controlled slope generator having a period P, connected to said deflecting means for scanning each line and delivering in response N recurrent pulses numbered respectively 1 . . . j . . . N of period P/N = τ said assembly of memories comprising a central memory and a first and second shift register memory, each memory of said assembly, comprising N two stable state stages significant of digits "0" and "1", said pulse numbered j addressing simultaneously the stages A j , B j , C j respectively of said first, said central and said second memory, means connected to said stage output for triggering said two bistable state device at time Jτ + τ/2 when the addressed stage Aj is in the "1" state, at time jτ when the addressed stage Bj is in the "1" state, at time jτ- τ/2 when stage Bj is in the "1" state.