ELECTRON EMISSION SEMICONDUCTOR DEVICE

摘要

An electron source having a rapid response time comprises at least one n-p-n structure (and possibly an array of said n-p-n structure) formed in a silicon or other semiconductor body (10) by a p-type first region (1) between n-type second and third regions (2 and 3). Electrons (24) are generated in the n-p-n structure (2,1,3) for emission into free space (20) from a surface area (4) of the body (10) after flowing from the second region (2) through the first and third regions (1 and 3). The n-p-n structure (2,1,3) has electrode connections (12 and 13) only to the n-type second and third regions (2 and 3). The first region (1) provides a barrier region restricting the flow of electrons from the second region (2) to the third region (3) until a potential difference (V) is applied between the electrode connections (12 and 13) to bias the third region (3) positive with respect to the second region (2) and to establish a supply of hot electrons (24) injected into the third region (3) with sufficient energy to overcome the potential barrier present between the surface area (4) and free space (20). The barrier region (1) forms depletion layers with both the n-type second and third regions (2 and b 3) and is depleted of holes by the merging together of these depletion layers at least when the potential difference (V) is applied to establish said supply of hot electrons (24). The n-p-n structure can be provided in a mesa portion (9) of the body (10) at a window in an insulating layer (11) so as to form a compact arrangement having very low associated capacitances. The electron sources may be used in cathode-ray tubes, display devices and even electron lithography equipment.