Solid-state array cameras
Abstract
Over the past few years there has been growing interest shown in the rapidly maturing technology of
totally solid-state imaging. This paper presents a synopsis of developments made in this field at the
Westinghouse ATL facilities with emphasis on row-column organized monolithic arrays of diffused junction
phototransistors. The complete processing sequence applicable to the fabrication of modern highdensity
arrays is described from wafer ingot preparation to final sensor testing. Special steps found
necessary for high yield processing, such as surface etching prior to both sawing and lapping, are discussed
along with the rationale behind their adoption. Camera systems built around matrix array photosensors
are presented in a historical time-wise progression beginning with the first 50 X 50 element converter
developed in 1965 and running through the most recent 400 X 500 element system delivered in 1972.
The freedom of mechanical architecture made available to system designers by solid-state array cameras
is noted from the description of a bare-chip packaged cubic inch camera. Hybrid scan systems employing
one-dimensional line arrays are cited, and the basic tradeoffs to their use are listed.