The Effect of Surface Treatments on Point-Contact Transistor Characteristics

Abstract

A description is given of the electrical properties of formed point contacts on germanium. A useful technique for observation of the equipotentials surrounding such contacts is described. The contrasting properties of donor‐free and donor‐doped contacts, used as diodes or transistor collectors are emphasized. It is shown that unformed point contacts (which have electrical properties largely determined by a surface barrier layer), may exhibit analogous differences. Such changes are produced by chemical treatments calculated to influence properties of a soluble germanium oxide film on the surface. The above information is applied to a study of transistor forming as it is done in present point‐contact transistor processing. It is shown that high yields from the forming process can be expected on oxidized surfaces, and that chemical washes which remove soluble germanium, oxide drastically lower forming yields. These and other effects are evaluated as sources of variability in forming yield.

A Forming Study of Point-Contact Tunnel Diodes

“…A number of papers were written discussing this phenomena, most of the work being either experimental results or theoretical work of a qualitative nature (5,6,7). This, however, was only.…”

“…There has been considerable interest (5,8,9) shown from time to time in the influence of surface effects on formed point contacts, a subject which we shall neglect on the assumption that -10-such effects are of relatively small significance in a low-impedance device such as a tunnel diode.…”

The Infrared Spectra of the Adsorbed Phase on Tantalum Oxide Films

“…Under appropriate conditions it has been used to determine adsorption isotherms (1)(2)(3)(4), and to establish the nature of an adsorbent (5,6) and the type of interaction between adsorbent-adsorbate (3,4). Further, it is known that the presence of an adsorbed phase on a solid can have a pronounced effect on the electrical properties of both the bulk and the surface of a solid (7)(8)(9)(10)(11)(12)(13)(14). As a particular example, it is known that the presence of an adsorbed layer of water can have a decided effect on the dielectric properties of many oxides (15,16) as anodic aluminum oxide (17) and anodic tantalum oxide (18).…”