Patent ID: 11923295
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 4:
5. A method of forming a semiconductor structure, the method comprising:
forming a high resistance layer over a first dielectric layer, the first dielectric layer being over a first conductive line, the first dielectric layer having a first thickness;
depositing a second dielectric layer over the high resistance layer, the second dielectric layer having a second thickness;
patterning the first dielectric layer, the second dielectric layer, and the high resistance layer, wherein patterning the high resistance layer removes a portion of the high resistance layer over the first conductive line, wherein, after patterning, the first dielectric layer has a third thickness over the first conductive line and the second dielectric layer has a fourth thickness, wherein the third thickness is less than the first thickness, wherein the fourth thickness is less than the second thickness, wherein the fourth thickness is substantially the same as the third thickness, and wherein during patterning an etch rate of the second dielectric layer is the same as the etch rate of the first dielectric layer;
depositing a low-k dielectric layer over the second dielectric layer and the first dielectric layer, the low-k dielectric layer covering sidewalls of the patterned high resistance layer;
forming a first conductive via through the second dielectric layer, the first conductive via extending into the high resistance layer to a depth in a range of 10 Å to 40 Å;
forming a second conductive via through the first dielectric layer, the second conductive via physically contacting the first conductive line; and
forming a second conductive line over the second conductive via, wherein a bottom corner of the second conductive line is lower than a top corner of the first conductive via and the bottom corner of the second conductive line is higher than a bottom surface of the first conductive via.