Advanced imaging techniques for submicrometer devices

As the dimensions of electronic circuits are reduced in the quest for higher performance and greater density, the limits of conventional imaging techniques are being reached. New imaging methods using electron beams and X‐rays rather than optical radiation are being developed in many laboratories. This paper gives an overview of work in our laboratory on high resolution electron beam and X‐ray lithography. The GaAs field effect microwave transistor is high‐lighted as an example of a device for which the increased cost of advanced imaging techniques is offset by the enhanced performance obtained.