Thyristor semiconductor memory device and method of manufacture
AssigneeT-RAM Semiconductor, Inc.
InventorAndrew E. Horch
Life of this patent
Estimating the term…
Abstract
A thyristor memory device may comprise a capacitor electrode formed over a base region of the thyristor using a replacement gate process. During formation of the thyristor, a base-emitter boundary may be aligned relative to a shoulder of the capacitor electrode. In a particular embodiment, the replacement gate process may comprise defining a trench in a layer of dielectric over semiconductor material. Conductive material for the electrode may be formed over the dielectric and in the trench. It may further be patterned to form a shoulder for the electrode that extends over regions of the dielectric over a base region for the thyristor. The extent of the shoulder may be used to pattern the dielectric and/or to assist alignment of implants for the base and emitter regions of the thyristor.
Claims11
A semiconductor device comprising:
- a thyristor having first and second base regions disposed serially between first and second emitter regions;
- a capacitor electrode comprising a surface disposed over at least one of the first and second base regions;
- dielectric of first thickness disposed between the surface of the capacitor electrode and the first base region;
- dielectric of second thickness disposed between the second base region and the surface of the capacitor electrode, the dielectric of second thickness substantially thicker than that of the first thickness;
- a foot disposed in spaced relationship over at least a portion of the first base region of the thyristor and separated therefrom by the dielectric of first thickness,
- a body extending upwardly from the foot, and
- at least one arm extending laterally outward from the body,
- one of the arm(s) over a portion of the second base and spaced therefrom, at least in part, by the dielectric of the second thickness.
Dependencies are inferred from the claim text.