Method for making bulk resistor and integrated circuit using the same

Claim 1

In a method for fabricating a bulk resistor formed from a single crystal semiconductor body carrying an impurity of one conductivity type and having a surface, forming V-shaped recesses in the body extending through said surface of the body by the use of an anisotropic etch, forming a layer of insulating material on said surface and in said V-shaped recesses, diffusing an impurity of opposite conductivity type in one region of the semiconductor body extending from said surface after the use of the anisotropic etch, forming a support body on said layer of insulating material, removing a portion of the semiconductor body opposite from said surface until the layer of insulating material in the V-shaped recesses is exposed to thereby provide a plurality of isolated islands of single crystal semiconductor material having surfaces laying in a common plane and being isolated from each other and from the support body by the layer of insulating material with at least one of said islands being formed of said region having an impurity of opposite conductivity type, forming a layer of insulating material on said surfaces lying in a common plane, forming active and passive devices in said islands with one of the passive devices being a bulk resistor formed solely of the material in said one island which has an impurity of opposite conductivity type therein, said bulk resistor being the sole device in said one island, providing a lead structure on said layer of insulating material on said surfaces lying in a common plane so that the lead structure includes contact elements extending through said layer of insulating material on said surfaces lying in a common plane and engaging the active and passive devices including the bulk resistor to interconnect the same.