Electron migration control in interconnect structures

• Main Authors: Hsu, Kai-Shiung, Lin, Jyh-nan, Liu, Ding-I, Chen, Chun-Jen
• Format: Patent
• Language: English
• Published: 01.03.2022
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

A method for improving reliability of interconnect structures for semiconductor devices is disclosed. The method includes forming a contact structure on a transistor and forming a metallization layer on the contact structure. The forming the metallization layer includes depositing an inter-metal dielectric (IMD) layer on the transistor, forming an opening within the IMD layer to expose a top surface of the contact structure, depositing a metallic layer to fill the opening, forming an electron barrier layer within the IMD layer, and forming a capping layer within the metallic layer. The electron barrier layer has a hole carrier concentration higher than a hole carrier concentration of a portion of the IMD layer underlying the electron barrier layer. The capping layer has a hole carrier concentration higher than a hole carrier concentration of a portion of the metallic layer underlying the capping layer.