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Propagating Signals Across Semiconductor Wafers

IP.com Disclosure Number: IPCOM000095331D
Original Publication Date: 1965-Nov-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

Farber, AS: AUTHOR

Abstract

This structure is for propagating signals of high velocity across semi-conductor wafers. The structure reduces the propagation delays encountered in high dielectric constant semiconductor materials.

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Propagating Signals Across Semiconductor Wafers

This structure is for propagating signals of high velocity across semi- conductor wafers. The structure reduces the propagation delays encountered in high dielectric constant semiconductor materials.

The velocity of signal propagation in a lossless dielectric is equal to v = C/ square root epsilon(r). Many materials for large-scale integrated circuits have a large relative dielectric constant and, therefore, a slow propagation velocity. For example, in semi-insulating GaAs with epsilon(r)=12, v = 3.49''/nsec. These slow velocities either significantly increase the delay in a logic system or, for a given delay, require a much higher packing density.

The structure is formed by first depositing and etching the conductor material in the standard manner. Then the supporting material is selectively etched away, leaving only periodic supports for the strip line. Several layers of metallurgy or a layer of insulator may be required between the supporting material and the main conductor in order to protect the back of the line from the etchant, The etch depth t1 need not be a major portion of the material thickness. This is

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The periodic supports increase this effective dielectric constant in proportion to the ratio of the supported to the unsupported line. It is, therefore, desirable to increase the distance between supports as long as it is small compared to lambda/4 of the propagating frequencies. The cutoff...