Patent ID: 11972975
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 8:
9. A method of forming a semiconductor device structure, comprising:
forming an insulating layer over a semiconductor substrate;
forming a conductive via in the insulating layer;
forming a masking structure over the insulating layer, wherein the masking structure has a trench opening that exposes the conductive via and comprises:
a first layer; and
a second layer formed over the first layer;
forming a conductive line in the trench opening to electrically connect the conductive via;
removing the second layer from the masking structure;
forming a thermal decomposable material in a space formed by the removal of the second layer, wherein an upper surface of the thermal decomposable material is lower than an upper surface of the metal line;
forming a capping liner to cover the upper surfaces of the thermal decomposable material and the metal line; and
removing the thermal decomposable material by a thermal process to form two air gaps adjacent to opposite sidewalls of the conductive line.