Barrier dielectric stack for seam protection

Abstract

The present invention provides a semiconducting device including a gate dielectric atop a semiconducting substrate, the semiconducting substrate containing source and drain regions adjacent the gate dielectric; a gate conductor atop the gate dielectric; a conformal dielectric passivation stack positioned on at least the gate conductor sidewalls, the conformal dielectric passivation stack comprising a plurality of conformal dielectric layers, wherein no electrical path extends entirely through the stack; and a contact to the source and drain regions, wherein the discontinuous seam through the conformal dielectric passivation stack substantially eliminates shorting between the contact and the gate conductor. The present invention also provides a method for forming the above-described semiconducting device.

Description

RELATED APPLICATIONS[0001]This application is a divisional application of U.S. Ser. No. 10 / 904,661, filed Nov. 22, 2004.FIELD OF THE INVENTION[0002]The present invention relates to semiconductor devices having enhanced resistance to shorting, and more particularly to metal oxide semiconductor field effect transistors (MOSFETS), in which electrical shorting between the gate conductor and the contacts to the source and drain regions of the device is substantially eliminated by a conformal dielectric passivation stack positioned on at least the sidewalls of the gate region. The inventive conformal dielectric passivation stack comprises at least a first conformal dielectric layer and a second conformal dielectric layer in which no electrical pathway is present that extends entirely through the stack. The absence of the electrical pathway can be achieved by using a second conformal dielectric that is seamless or one in which the seams are offset from the seams present in the first dielec...

AI Technical Summary

Benefits of technology

[0008]An object of the present invention is to provide a field effect transistor (FET) having a passivation stack comprising at least two passivation layers in which a discontinuous electrical pathway through the passivation stack is provided. In particular, this objective is achieved in the present invention by providing a conformal dielectric layered stack positioned on at least the sidewall portions of the gate conductor, in which a first dielectric layer of the conformal dielectric stack has seams which are covered by a second dielectric layer. The second dielectric may contain seams or it may be seamless. When the second dielectric is seamless, a discontinuous seam is provided in the dielectric stack thereby preventing the formation of a complete electrical pathway to the adjacent metal contact. It is noted that seams are generally introduced into the first dielectric layer because of the difference in step height within the structure.

Problems solved by technology

This electrical path can, in turn, result in device shorting.

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