DE2526429

1488728 Resistors; semi-conductor devices SONY CORP 9 June 1975 [18 June 1974] 24658/75 Headings HIS and H1K A thin film resistor comprises a polycrystalline silicon film, containing oxygen in the range 2 to 45 atomic per cent, and electrical contacts 14, 15. As shown, resistive film 13 is formed on the same substrate 1 as a transistor 8, Fig. 1, or a film 33 is used as the gate resistor of a resistance gate type FET, Fig. 6. In the embodiment of Fig. 1 film 13 is deposited over a silicon dioxide film 9 and is covered with a further silicon dioxide film 16. The ends of film 13 may be doped with boron or phosphorus to provide good contact with 14, 15. Film 13 is deposited by the thermal decomposition of a mixed gas of SiH 4 and N 2 O, and the resistivity may be controlled by varying the ratio of these two gases. In the embodiment of Fig. 6, FET gate electrode 27 is connected to resistive film 33 which is capacitatively coupled to channel 26 between source 22 and drain 23. As shown a film 33 is surrounded by silicon dioxide film 29, but it may be formed on film 29 or directly on the semi-conductor substrate 21.