Sgs-Thomson Microelectronics Limited

Stmicroelectronics Gmbh

Michael E Haslam

Charles R Spinner, Iii

Gregory J Stagaman

A method is provided for reducing the reflectivity of a metal layer prior to photolithography. A thin buffer layer, such as oxide, can be deposited over the metal layer. A short plasma etch is performed in order to roughen, but not completely remove, the thin oxide layer. This roughened layer significantly reduces the reflectivity of the underlying metal layer. As an alternative, the brief plasma etch can be applied directly to the metal layer, which results in a significant roughening of its upper surface. This also reduces the reflectivity of the metal layer.

Method for reducing reflectivity of a metal layer

A structure and method for forming contact structures in integrated circuits. A buffer layer is formed over an underlying conductive element. A first conductive layer is then deposited over the buffer layer and patterned to define a first interconnect layer. While the first interconnect layer is patterned, the buffer layer protects the underlying conductive element from damage. Portions of the buffer layer which are not covered by the first interconnect layer are then removed, and a second conductive layer is deposited over the integrated circuit. The second conductive layer is then anisotropically etched to form conductive sidewall spacers alongside the vertical sidewalls of the first interconnect layer, where at least one of the conductive sidewall spacers makes electrical contact with the underlying conductive element. Therefore, a conductive contact is made between the underlying conductive element and the first interconnect layer through at least one of the conductive sidewall spacers.

Method for forming contact structures in integrated circuits

Structure and method for forming contact structures in integrated

A structure and method for forming contact vias in integrated circuits. An interconnect layer is formed on an underlying layer in an integrated circuit. A buffer region is then formed adjacent to the interconnect layer, followed by forming an insulating layer over the integrated circuit. Preferably, the insulating layer is made of a material which is selectively etchable over the material in the buffer region. A contact via is then formed through the insulating layer to expose a portion of the interconnect layer. During formation of the contact via, the buffer region acts as an etch stop and protects the underlying layer. The buffer region also ensures a reliable contact will be made in the event of an error in contact via placement.

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Highland Village, TX, United States of America

Michael E Haslam