Taiwan Semiconductor Manufacturing Comp. Ltd.

Mei-Hui Sung

Ming-Huei Lui

Yuan-Hung Chiu

Peng-Fu Hsu

Baw-Ching Perng

Lawrence Mh Lui

Meng-Huei Lui

A method is described for selectively etching a high k dielectric layer that is preferably a hafnium or zirconium oxide, silicate, nitride, or oxynitride with a selectivity of greater than 2:1 relative to silicon oxide, polysilicon, or silicon. The plasma etch chemistry is comprised of one or more halogen containing gases such as CF, CHF, CHF, CHF, CF, CF, CF, BCl, Br, HF, HCl, HBr, HI, and NFand leaves no etch residues. An inert gas or an inert gas and oxidant gas may be added to the halogen containing gas. In one embodiment, a high k gate dielectric layer is removed on portions of an active area in a MOS transistor. Alternatively, the high k dielectric layer is used in a capacitor between two conducting layers and is selectively removed from portions of an ILD layer.

Zirconium oxide and hafnium oxide etching using halogen containing chemicals

A method is disclosed for forming dual damascene structures with a multi-purpose composite mask. The composite mask serves not only to prevent via poisoning, but also to improve the lithographic characteristics of forming a dual damascene structure. This is accomplished by using a mask comprising silicon-based as well as polymeric dielectric layers. Thus, one of the components of the composite mask, namely, the polymeric dielectric, makes it possible to protect the via openings by conformally covering the sidewalls of the via and, at the same time, by bringing controllability to the height of the protective dielectric in the via opening. In addition, because the polymeric dielectric also serves as the main plasma resisting layer during the trench etch, the required photoresist is much thinner; therefore, the lithography process window can be extended beneficially.

Multi-purpose composite mask for dual damascene patterning

An improved and new process for photoresist stripping for use during fabrication of semiconductor integrated circuits, which use porous low-k dielectric materials, such as OSG or HSQ, as the interlevel and intra-level insulating layers, has been developed. Photoresist stripping in microwave or rf generated plasmas in gaseous mixtures of NH and CO takes place without attack or damage to underlying layers of OSG or HSQ. Optimum results are obtained when the ratio of CO to NH is between about 0.8 and 1.2.

Method of resist stripping over low-k dielectric material

Within a dual damascene method for forming a dual damascene aperture within a microelectronic fabrication there is employed an etch stop layer interposed between a first dielectric layer and second dielectric layer within a non active product region of a substrate, but not within an active product region of the substrate. Within the dual damascene method, an endpoint for forming a trench within a dual damascene aperture within the active product region is sensed by reaching the etch stop layer when forming a dummy trench within the non active product region.

Method for forming a dual damascene aperture while employing a peripherally localized intermediate etch stop layer

Within a dual damascene method for forming a dual damascene aperture within a microelectronic fabrication there is employed a bottom etch stop layer formed of a first material and an intermediate etch stop layer formed as a laminate of a second material having formed thereupon a third material. Within the method, the second material serves as an etch stop for the first material and the third material, which may be identical materials. Within the method, there may be etched completely through the bottom etch stop layer to reach a contact region formed there beneath while not etching completely through the intermediate etch stop layer to reach a first dielectric layer formed there beneath.

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Hsin-Chu, Taiwan

Mei-Hui Sung