Sandwich-type structure, providing novel resistor configurations

Discusses the problem of placing high value resistors on very small size semiconductor integrated circuits. Diffused monolithic resistors cannot give high values and even the use of deposited thin film resistors is handicapped by the lack of available surface area. After discussing the processes and limitations of planar resistor structures, a sandwich resistor structure is suggested using a high resistance semiconducting compound. The construction of the sandwich resistor is similar to the standard thin film capacitor. The high resistivity material is deposited between two overlapping thin film conductors; the resistance is developed within the area of the overlap and the result is a parallel resistor-capacitor network. Fabrication techniques are discussed and results on test patterns are quoted.