Low resistance through-wafer via
AssigneeÅAC Microtec AB
InventorPeter Nilsson
Life of this patent
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Abstract
The present invention provides a wafer (3) comprising a through-wafer via (7) through the wafer (3) formed by a through-wafer via hole (9) and at least a first conductive coating (25). A substantially vertical sidewall (11) of the through-wafer via hole (9) except for a constriction (23) provides a reliable through-wafer via (7) occupying a small area on the wafer. The wafer (3) is preferably made of a semiconductor material, such as silicon, or a glass ceramic. A method for manufacturing such a wafer (3) is described.
Claims21
1-33. (canceled)
A wafer comprising a through-wafer via from an upper side to a lower side of the wafer, wherein the through-wafer via comprises a through wafer via hole having a sidewall at least partly covered with a first conductive coating, wherein the through wafer via hole comprises at least a first portion with a substantially vertical sidewall and a second portion that forms a constriction with at least an upper sloping sidewall widening out towards the upper side in the through wafer via hole.
A method for manufacturing a wafer comprising a through-wafer via extending from an upper side to a lower side of the wafer, wherein the through-wafer via comprises a through-wafer via hole having a sidewall and the at least a first portion of the through-wafer via hole has a substantially vertical sidewall and a second portion of the through-wafer via hole defines a constriction in the through-wafer via hole, wherein the method comprises the steps of:
- defining at least a first sloping sidewall in the wafer;
- forming the through-wafer via hole, whereby the upper sloping sidewall of the constriction replicates the first sloping sidewall;
- and
- depositing at least a first conductive coating on the sidewall of the through-wafer via hole.
The method according to 45, wherein the step of forming the through-wafer via hole comprises the step of two-way etching from the upper and lower sides to form a third portion of the through-wafer via hole having a substantially vertical sidewall.
Dependencies are inferred from the claim text.