Other

National University of Singapore

Institute of Microelectronics

Chartered Semiconductor Manu. Ltd.

Wye Boon Loh

Lap Chan

Kheng Chok Tee

Kuan Pei Yap

Flora S Ip

Choi Pheng Soo

An interconnect line on an IMD layer on a semiconductor device is formed in an interconnect hole in the IMD layer. The interconnect hole has walls and a bottom in the IMD layer. A diffusion barrier is formed on the walls and the bottom of the hole. Fill the interconnect hole with a copper metal line. Perform a CMP step to planarize the device and to remove copper above the IMD layer. Deposit a passivating metal layer on the surface of the copper metal line encapsulating the copper metal line at the top of the hole. Alternatively, a blanket deposit of a copper metal line layer covers the diffusion layer and fills the interconnect hole with a copper metal line. Perform a CMP process to planarize the device to remove copper above the IMD layer. Deposit a passivating metal layer on the surface of the copper metal line encapsulating the copper metal line at the top of the hole in a self-aligned deposition process.

Passivation of copper interconnect surfaces with a passivating metal layer

Only one photo mask defines the metal trench and via region. The mask blocks the UV light in the trench and via area forming Plasma Polymerized Methylsilane Oxide (PPMSO) in the exposed areas. Two step RIE plasma treatment using chlorine gas and oxygen gas removes the Plasma Polymerized Methylsilane (PPMS) in the trench and via regions. Conductive metal is deposited. A CMP process polishes back both excess metal along with the PPMSO, at a similar rate, to form: conducting metal lines, interconnects, and via contacts without metal dishing.

Simplified dual damascene process utilizing PPMSO as an insulator layer

Passivation of copper interconnect surfaces with a passivating metal

Growing community of inventors

Johor, Malaysia

Wye Boon Loh