Manufacturing TaSi-polysilicon conductors having high-resistance elements by a liftoff technique

Claim 1

A process for manufacturing high-resistance elements as part of an integrated circuit production procedure, in which access lines to certain elementary transistor terminals are formed of conducting strips, obtained by superimposing a strip of strongly doped polycrystalline silicon and a strip of metal silicide, such resistors being positioned at places where the integrated circuit surface is coated with a thick layer of oxide, said process comprising the following steps: depositing on an oxide coated integrated circuit surface a layer of polycrystalline silicon possessing high resistivity; depositing on said polycrystalline silicon layer at places where resistors are required plugs of photosensitive substance; doping the polycrystalline silicon to endow it with low resistivity except at places protected by said photosensitive substance; depositing a silicide over the entire surface of the integrated circuit including the unmasked polycrystalline silicon and the plugs; removing by chemical lift-off the photosensitive plugs and portions of silicide covering them; selectively masking and etching said silicide and polycrystalline silicon to form said lines, some at least of which pass over the plug positions.