Applied Materials, Inc.

Barney M Cohen

Kenny King-Tai Ngan

Suraj Rengarajan

Ted Tie Guo

Bradley Owen Stimson

Amrita Verma

Xiangbing Li

Jingang Su

Zheng Xu

Vijay D Parkhe

John C Forster

Peijun Ding

Murali K Narasimhan

Kenny King-tai Ngan

Gilbert Hausmann

Debabrata Ghosh

Yoichiro Tanaka

Jr-Jyan Chen

Megumi Taoka

George Proulx

Mohamed A Al-Sharif

The present invention provides a method and apparatus for precleaning a patterned substrate with a plasma comprising a mixture of argon, helium, and hydrogen. Addition of helium to the gas mixture of argon and hydrogen surprisingly increases the etch rate in comparison to argon/hydrogen mixtures. Etch rates are improved for argon concentrations below about 75% by volume. RF power is capacitively and inductively coupled to the plasma to enhance control of the etch properties. Argon, helium, and hydrogen can be provided as separate gases or as mixtures.

Plasma preclean with argon, helium, and hydrogen gases

The present invention generally provides a method for improving fill and electrical performance of metals deposited on patterned dielectric layers. Apertures such as vias and trenches in the patterned dielectric layer are etched to enhance filling and then cleaned in the same chamber to reduce metal oxides within the aperture. The invention also provides cleaning the patterned dielectric layer in a processing chamber with a first plasma consisting essentially of argon, wherein the first plasma is generated by supplying power to a coil surrounding the processing chamber and supplying bias to a substrate support member supporting the substrate, cleaning the patterned dielectric layer in the processing chamber with a second plasma consisting essentially of hydrogen and helium, wherein the second plasma is generated by increasing the supply of power to the coil surrounding the processing chamber and reducing the supply of bias to the substrate support member supporting the substrate, depositing a barrier layer on the patterned dielectric layer after exposing the dielectric layer to the first plasma and the second plasma, and depositing a metal on the barrier layer. Furthermore, the sequential plasma treatments can be practiced in a variety of plasma processing chambers of an integrated process sequence, including pre-clean chambers, physical vapor deposition chambers, etch chambers, and other plasma processing chambers.

Sequential sputter and reactive precleans of vias and contacts

The invention is a precleaning process suitable for fabricating metal plugs in a low-&kgr;, carbon-containing dielectric. More specifically, the invention is a process for cleaning a contact area of a metal conductor on a semiconductor workpiece so as to minimize damage to a low-&kgr;, carbon-containing dielectric overlying the metal. After forming contact openings in the low-&kgr; dielectric so as to expose contact areas on the underlying metal conductor, the contact areas are cleaned by exposing the workpiece to an atmosphere formed by plasma decomposition of a mixture of hydrogen-containing and helium gases. Surprisingly, our preclean process can repair damage to the dielectric caused by preceding process steps, such as oxygen plasma ashing processes for removing photoresist.

Precleaning process for metal plug that minimizes damage to low-&kgr; dielectric

The invention generally provides an apparatus and a method of removing metal oxides, particularly copper oxides and aluminum oxides, from a substrate surface. Primarily, the invention eliminates sputtering of copper oxide from the bottom of an interconnect feature onto the side walls of an interconnect feature, thereby preventing diffusion of the copper atom through the dielectric material and degradation of the device. The invention also eliminates sputtering of the copper oxides onto the chamber side walls that may eventually flake off and cause defects on the substrate. The method of reducing metal oxides from a substrate surface comprises placing the substrate within a plasma processing chamber, flowing a processing gas comprising hydrogen into the chamber, and maintaining a plasma of the processing gas within the chamber through inductive coupling. The method is preferably performed using a dual frequency etch chamber wherein adjustments are made in the processing gas flow, the RF powers and the exhaust pumping speeds to eliminate sputtering of the copper oxide and to maximize the reduction reaction.

Reduction of metal oxide in a dual frequency etch chamber

A method of cleaning a contact area of a semiconductor or metal region on a substrate of an electronic device. First, the contact area is cleaned by exposing the substrate to a plasma that includes fluorine-containing species. Second, the substrate is exposed to a second atmosphere that scavenges fluorine, preferably formed by plasma decomposition of a hydrogen-containing gas. The second atmosphere removes any fluorine residue remaining on the contact area and overcomes any need to include argon sputtering in the cleaning process. Another aspect of the invention is a method of depositing a refractory metal over a contact area of a semiconductor region on a substrate. The contact area is cleaned according to the two-step process of the preceding paragraph. Then a refractory metal is deposited over the contact area. The two-step cleaning process can reduce the electrical resistance between the refractory metal and the semiconductor region. Furthermore, if the substrate is annealed to interdiffuse atoms of the semiconductor material and the refractory metal, the two-step cleaning process can reduce the anneal temperature required to achieve a desired low electrical resistance.

Cleaning contact with successive fluorine and hydrogen plasmas

Native oxides can be removed from a substrate having high aspect ratio openings therein by using a plasma gas precursor mixture of a reactive halogen-containing gas and a carrier gas such as helium. The lightweight ions generated in the plasma react with oxygen to produce very volatile oxygen-containing species that can be readily removed through the exhaust system of the plasma chamber, preventing re-deposition of oxides on the surface of the substrate or on the sidewalls or bottom of the openings. When the substrate is mounted in a plasma chamber having dual power sources that can form a plasma above the substrate and can apply bias to the substrate, tapered openings are formed rapidly that can be readily filled without forming voids.

Reactive plasma etch cleaning of high aspect ratio openings

A method of stabilizing a halogen-doped silicon oxide film to reduce halogen atoms migrating from said film during subsequent processing steps. A halogen-doped film is deposited over a substrate and then subjected to a degassing step in which the film is briefly heated to a temperature of between about 300 and 550.degree. C. before deposition of a diffusion barrier layer. It is believed that such a heat treatment step removes loosely bonded halogen atoms from the halogen-doped film and thus the treatment is referred to as a degassing step. In a preferred version of this embodiment, the halogen-doped silicon oxide film is an FSG film that is subjected to a degassing treatment for between about 35 and 50 seconds.

Thermal post-deposition treatment of halogen-doped films to improve film

The invention generally provides an apparatus that reduces backside sputtering of the substrate in a pre-clean chamber and other etch chambers. The invention also provides an apparatus that reduces flaking of material from the film formed on the surfaces of the process kit and extends the specified lifetime of a process kit. One aspect of the invention provides an apparatus for supporting a substrate, comprising a support pedestal contacting a central portion of the substrate and an insulator surrounding the support pedestal, the insulator having a beveled portion extending from a circumferential edge of the substrate.

Pedestal insulator for a pre-clean chamber

A method of stabilizing a halogen-doped silicon oxide film to reduce halogen atoms migrating from said film during subsequent processing steps. A halogen-doped film is deposited over a substrate and then subjected to a degassing step in which the film is briefly heated to a temperature of between about 300.degree. and 550.degree. C. before deposition of a diffusion barrier layer. It is believed that such a heat treatment step removes loosely bonded halogen atoms from the halogen-doped film and thus the treatment is referred to as a degassing step. In a preferred version of this embodiment, the halogen-doped silicon oxide film is an FSG film that is subjected to a degassing treatment for between about 35 and 50 seconds.

A pedestal for supporting a semiconductor substrate in an R.F. plasma reactor chamber includes a conductive disk platen having a diameter exceeding the diameter of the substrate so that an outer annular portion of the conductive disk platen provides a direct path of R.F. power from the plasma while a remaining inner portion of the conductive disk provides a path of R.F. power from the plasma through the substrate, an etch-resistant cover shielding the conductive platen from the plasma, a portion of the etch-resistant layer underlying the substrate, the etch-resistant cover including a raised disk overlying a central portion of the conductive disk platen and underlying the substrate and having a diameter less than the diameter of the substrate so that a peripheral portion of the substrate extends beyond the circumference of the raised disk, a recessed ring annulus overlying an outer portion of the conductive disk platen and having a top surface which is depressed below a top surface of the raised disk, an inner portion of the recessed ring annulus underlying the peripheral portion of the substrate, leaving a top portion of a side wall of the raised disk exposed to the plasma.

R.F. plasma reactor with larger-than-wafer pedestal conductor

A plasma reactor for carrying out plasma processing of a semiconductor substrate includes a vacuum chamber including apparatus for introducing a gas into the interior thereof, an induction coil encircling a region of the vacuum chamber, the coil being connected across an RF power source, and an electrode positioned adjacent the region and connected to the RF power source for capacitively coupling RF power to the gas in the interior of the vacuum chamber. The electrode has a surface area facing the region which is large enough to provide capacitive coupling of RF power to the gas in the region sufficient to facilitate igniting a plasma, but which is small enough so that, during steady-state maintenance of the plasma, most of the RF power coupled to the plasma from the RF power source is coupled inductively rather than capacitively.

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Santa Clara, CA, United States of America

Barney M Cohen