Matsushita Electric Industrial Co., Ltd.

Osamaru Eguchi

Shinji Fujiwara

Masakazu Fukai

Hiroyuki Serizawa

Yukimasa Kuramoto

A target for an image pickup tube having high sensitivity, low dark current and low amount of lag-image is manufactured by forming a hetero-junction by the evaporation process. A first layer of ZnS.sub.x Se.sub.1.sub.-x or Zn.sub.u Cd.sub.1.sub.-u S (wherein 0 .ltoreq. x .ltoreq. 1 and 0 .ltoreq. u .ltoreq. 1) is deposited on a light transmitting substrate having a coefficient of linear expansion of 56 .times. 10.sup..sup.-7 /.degree.C - 110 .times. 10.sup..sup.-7 /.degree.C and a second layer of (Zn.sub.y Cd.sub.1.sub.-y Te).sub.z (In.sub.2 Te.sub.3).sub.1.sub.-z (wherein 0.1 .ltoreq. y .ltoreq. 0.9 and 0.7 .ltoreq. z .ltoreq. 1) is deposited on the first layer. The substrate is then heat treated in an inert gas atmosphere or under vacuum at a temperature of 350.degree.-650.degree.C, preferably 500.degree.-600.degree.C for a time period of 5-90 minutes, preferably 5-15 minutes. By effecting second heat treatment at a temperature lower than the first heat treatment temperature, preferably at a temperature of 150.degree.-400.degree.C for 20 minutes - 3 hours, the characteristics of the target are further improved.

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Higashiosaka, Japan

Osamaru Eguchi