Buried power rail contact formation
AssigneeImec Vzw
InventorZheng Tao
Life of this patent
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Abstract
A method is provided for forming a semiconductor product including providing a substrate comprising a buried power rail; forming a sacrificial plug at a contact surface on the buried power rail; applying a front-end-of-line module for forming devices in the semiconductor substrate; providing a Via, through layers applied by the front-end-module, which joins the sacrificial plug on the buried power rail; selectively removing the sacrificial plug thereby obtaining a cavity above the buried power rail; filling the cavity with a metal to electrically connect the devices with the buried power rail, wherein the sacrificial plug is formed such that the contact surface area is larger than an area of a cross-section of the Via parallel with the contact surface.
Claims15
A method for forming a semiconductor product comprising a buried contact with a buried power rail, the method comprising:
- providing a semiconductor substrate comprising the buried power rail;
- forming a sacrificial plug at a contact surface on the buried power rail;
- applying a front-end-of-line module for forming devices in the semiconductor substrate;
- providing a Via through layers applied by the front-end-of-line module, which joins the sacrificial plug on the buried power rail;
- selectively removing the sacrificial plug thereby obtaining a cavity above the buried power rail;
- and
- filling the cavity with a metal to electrically connect the devices with the buried power rail, wherein the sacrificial plug is formed such that an area of the contact surface is larger than an area of a cross-section of the Via parallel with the contact surface.
Dependencies are inferred from the claim text.