Method for forming an air gap around a through-silicon via
AssigneeGlobalfoundries Singapore Pte. Ltd.
InventorsHong Yu, Huang Liu
Life of this patent
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Abstract
Semiconductor devices with air gaps around the through-silicon via are formed. Embodiments include forming a first cavity in a substrate, filling the first cavity with a sacrificial material, forming a second cavity in the substrate, through the sacrificial material, by removing a portion of the sacrificial material and a portion of the substrate below the sacrificial material, filling the second cavity with a conductive material, removing a remaining portion of the sacrificial material to form an air gap between the conductive material and the substrate, and forming a cap over the air gap.
Claims17
A device comprising:
- a substrate;
- a conductive material extending into the substrate;
- an air gap extending into the substrate, between at least part of the conductive material and the substrate;
- a cap having a portion over the air gap, and a portion within the air gap, the portion within the air gap extending from a first portion of the cap at the top of the air gap to a second portion of the cap within the air gap;
- a first oxide layer between the air gap and the substrate;
- a second oxide layer extending into the substrate between the air gap and the conductive material, the second oxide layer surrounding side and bottom surfaces of the conductive material;
- and
- a metal liner formed between the second oxide layer and the conductive material, wherein the second oxide layer is in direct contact with the metal liner.
A device comprising:
- a substrate;
- a transistor on the substrate;
- a through-silicon via (TSV) through the substrate, spaced from the transistor less than 1 micron (μm), the TSV having a diameter of 5 μm to 50 μm, wherein the TSV comprises:
- a conductive material extending through the substrate;
- an air gap extending from an air gap opening into the substrate, surrounding at least a portion of the conductive material, between the conductive material and the substrate;
- a cap over the air gap;
- a nitride layer over the substrate, coplanar with the air gap opening;
- a first oxide layer between the air gap and the substrate;
- a second oxide layer extending through the substrate between the air gap and the conductive material, the second oxide layer surrounding side and bottom surfaces of the conductive material;
- and
- a metal liner formed between the second oxide layer and the conductive material, wherein the second oxide layer is in direct contact with the metal liner.
A device comprising:
- a substrate;
- a transistor on the substrate;
- a through-silicon via (TSV) through the substrate, spaced from the transistor less than 1 micron (μm), the TSV having a diameter of 5 μm to 50 μm, wherein the TSV comprises:
- a conductive material extending through the substrate;
- an air gap extending from an air gap opening into the substrate, surrounding at least a portion of the conductive material, between the conductive material and the substrate;
- a first oxide layer formed to a thickness of 200 to 2000 Å between the air gap and the substrate;
- a second oxide layer formed to a thickness of 100 to 3000 Å between the air gap and the conductive material, the second oxide layer surrounding side and bottom surfaces of the conductive material;
- a metal liner comprising tantalum (Ta)/tantalum nitride (TaN), titanium (Ti)/titanium nitride (TiN), tungsten (W)/tungsten nitride (WN), or ruthenium (Ru) formed to a thickness of 100 to 3000 Å between the second oxide layer and the conductive material;
- a cap over the air gap;
- and
- a nitride layer over the substrate, coplanar with the air gap opening,
- wherein the second oxide layer is in direct contact with the metal liner.
Dependencies are inferred from the claim text.