Intermolecular, Inc.

J Watanabe

Chi-I Lang

Frank Greer

Ratsamee Limdulpaiboon

Sandip Niyogi

Abhijit Pethe

Amol Ramesh Joshi

Kevin Kashefi

Ashish Bodke

Albert Sanghyup Lee

Edwin Adhiprakasha

Wenxian Zhu

Jingang Su

Kurt Pang

Native oxide growth on germanium, silicon germanium, and InGaAs undesirably affects CET (capacitive equivalent thickness) and EOT (effective oxide thickness) of high-k and low-k metal-oxide layers formed on these semiconductors. Even if pre-existing native oxide is initially removed from the bare semiconductor surface, some metal oxide layers are oxygen-permeable in thicknesses below about 25 &#x212b; thick. Oxygen-containing species used in the metal-oxide deposition process may diffuse through these permeable layers, react with the underlying semiconductor, and re-grow the native oxide. To eliminate or mitigate this re-growth, the substrate is exposed to a gas or plasma reductant (e.g., containing hydrogen). The reductant diffuses through the permeable layers to react with the re-grown native oxide, detaching the oxygen and leaving the un-oxidized semiconductor. The reduction product(s) resulting from the reaction may then be removed from the substrate (e.g., driven off by heat).

Reduction of native oxides by annealing in reducing gas or plasma

Methods and apparatus for processing using a remote plasma source are disclosed. The apparatus includes an outer chamber enclosing a substrate support, a remote plasma source, and a showerhead. A substrate heater can be mounted in the substrate support. A transport system moves the substrate support and is capable of positioning the substrate. The plasma system may be used to generate activated species. The activated species can be used to treat the surfaces of low-k and/or ultra low-k dielectric materials to facilitate improved deposition of diffusion barrier materials.

Plasma treatment of low-K surface to improve barrier deposition

Methods and apparatus for processing using a remote plasma source are disclosed. The apparatus includes an outer chamber enclosing a substrate support, a remote plasma source, and a showerhead. A substrate heater can be mounted in the substrate support. A transport system moves the substrate support and is capable of positioning the substrate. The plasma system may be used to generate activated hydrogen species. The activated hydrogen species can be used to etch/clean semiconductor oxide surfaces such as silicon oxide or germanium oxide.

Hydrogen plasma cleaning of germanium oxide surfaces

Oxides (e.g., native or thermal silicon oxide) are etched from underlying silicon with a mixture of fluorine and oxygen radicals generated by a remote plasma. The oxygen radicals rapidly oxidize any uncovered bare silicon areas, preventing the pitting that can result from fluorine etching bare silicon more rapidly than it etches the surrounding oxide. A very thin (few &#x212b;), highly uniform passivation layer remaining on the silicon after the process may be left in place or removed. An oxygen-impermeable layer may be formed in-situ immediately afterward to prevent further oxidation. A pre-treatment with oxygen radicals alone fills pores and gaps in the oxide before etching begins.

Oxide removal by remote plasma treatment with fluorine and oxygen radicals

A germanium-containing semiconductor surface is prepared for formation of a dielectric overlayer (e.g., a thin layer of high-k gate dielectric) by (1) removal of native oxide, for example by wet cleaning, (2) additional cleaning with hydrogen species, (3) in-situ formation of a controlled monolayer of GeO, and (4) in-situ deposition of the dielectric overlayer to prevent uncontrolled regrowth of native oxide. The monolayer of GeOpromotes uniform nucleation of the dielectric overlayer, but it too thin to appreciably impact the effective oxide thickness of the dielectric overlayer.

Nucleation interface for high-k layer on germanium

Growing community of inventors

San Jose, CA, United States of America

J Watanabe