Critical fabrication processes for programmable HACT DPTFs

Author

Miller, R.L. ; Bailey, D.S. ; Blais, P. ; Henry, G. ; Sopira, M. ; Eldridge, G. ; Messham, R.

Author_Institution

Westinghouse Electronic Systems Group, Baltimore, MD, USA

fYear

1991

fDate

8-11 Dec 1991

Firstpage

31

Abstract

The type of acoustic charge transport (ACT) device which has generated the most widespread interest among electronics system designers is the digitally programmable transversal filter (DPTF). A heterojunction ACT (HACT) DPTF, having 128 taps with 5-b tap resolution and on-chip buffer amplifiers for input and output, is described. The device is being fabricated by a combination of epitaxial and ion-implantation processes, and it employs three metal layers. In addition to providing very high resolution for fine-line lithography and large depth of field for the nonplanar circuits in a HACT DPTF, E-beam lithography allows easy adjustment of critical circuit elements to adjust for parasitics, without the need to generate new mask layers. A discussion of the expected performance of this device is presented

Keywords

digital filters; electron beam lithography; surface acoustic wave filters; acoustic charge transport; digitally programmable transversal filter; electronics system designers; epitaxial; fine-line lithography; heterojunction ACT; ion-implantation processes; large depth of field; nonplanar circuits; on-chip buffer amplifiers; programmable HACT DPTFs; three metal layers; Acoustic devices; FETs; Fabrication; Flexible printed circuits; Gallium arsenide; Heterojunctions; Impedance; Lithography; MMICs; Transversal filters;

fLanguage

English

Publisher

ieee

Conference_Titel

Ultrasonics Symposium, 1991. Proceedings., IEEE 1991

Conference_Location

Orlando, FL

Type

conf

DOI

10.1109/ULTSYM.1991.234115

Filename

234115