ANISOTROPIC DIELECTRIC MATERIAL GATE SPACER FOR A FIELD EFFECT TRANSISTOR

摘要

Capacitive coupling between a gate electrode and underlying portions of the source and drain regions can be enhanced while suppressing capacitive coupling between the gate electrode and laterally spaced elements such as contact via structures for the source and drain regions. A transistor including a gate electrode and source and drain regions is formed employing a disposable gate spacer. The disposable gate spacer is removed to form a spacer cavity, which is filled with an anisotropic dielectric material to form an anisotropic gate spacer. The anisotropic dielectric material is aligned with an electrical field such that lengthwise directions of the molecules of the anisotropic dielectric material are aligned vertically within the spacer cavity. The anisotropic gate spacer provides a higher dielectric constant along the vertical direction and a lower dielectric constant along the horizontal direction.

主权项

1. A semiconductor structure containing a field effect transistor, said field effect transistor comprising:
a body region laterally contacted by a source region and a drain region; a gate dielectric contacting said body region; a gate electrode contacting said gate dielectric; and a gate spacer comprising an anisotropic dielectric material having an anisotropic dielectric constant and laterally surrounding said gate electrode.