News Column

Researchers Submit Patent Application, "Non-Lithographic Line Pattern Formation", for Approval

February 20, 2014



By a News Reporter-Staff News Editor at Politics & Government Week -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors Tseng, Chiahsun (Wynantskill, NY); Horak, David V. (Essex Junction, VT); Yeh, Chun-chen (Clifton Park, NY); Yin, Yunpeng (Niskayuna, NY), filed on July 30, 2012, was made available online on February 6, 2014.

The patent's assignee is International Business Machines Corporation.

News editors obtained the following quote from the background information supplied by the inventors: "The present disclosure relates to a method of patterning a structure, and more particularly to a non-lithographic method of patterning a structure employing successive mask erosion, and structures formed by the same.

"Semiconductor device scaling has been limited by the limitations of lithographic tools. For example, dimensions of minimum printable features have been limited by the capabilities of available lithographic tools to print such features. The slow progress in the capabilities of lithographic tools in recent years has made it difficult to aggressively scale the pitch of line level patterns near critical dimensions."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "A metal layer is deposited over an underlying material layer. The metal layer includes an elemental metal that can be converted into a dielectric metal-containing compound by plasma oxidation and/or nitridation. A hard mask portion is formed over the metal layer. Plasma oxidation and/or nitridation is performed to convert physically exposed surfaces of the metal layer into the dielectric metal-containing compound. Surface portions of the hard mask portion are pulled back to physically expose surfaces of the metal layer, and trenches are formed through the metal layer in the newly exposed area. Additional surface portions of the hard mask portion are pulled back, and physically exposed top surfaces of the metal layer are converted into the dielectric metal-containing compound. The sequence of a surface pull back of the hard mask portion, trench etching, another surface pull back, and conversion of top surfaces into the dielectric metal-containing compound are repeated to form a line pattern having a spacing that is not limited by lithographic minimum dimensions.

"According to an aspect of the present disclosure, a method of forming a lithographic structure is provided. A metal layer is formed on an underlying material layer. A hard mask portion is formed on the metal layer. A first surface portion of the metal layer is converted into a dielectric metal-containing compound portion employing the hard mask portion as a masking structure. A top surface of a second surface portion of the metal layer is physically exposed by isotropically recessing physically exposed surfaces of the hard mask portion. An outer periphery of the second surface portion coincides with an inner periphery of the dielectric metal-containing compound portion.

"According to another aspect of the present disclosure, a patterned structure is provided, which includes a patterned layer located on an underlying material layer. The patterned layer includes a first stack including a first metal portion and a first dielectric metal-containing compound portion contacting a top surface of the first metal portion. The patterned layer further includes a second stack including a second metal portion and a second dielectric metal-containing compound portion overlying a peripheral portion of the second metal portion. Outer sidewalls of the second stack are laterally spaced from inner sidewalls of the first stack by a same distance throughout an entire periphery of the second stack.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

"FIG. 1A is a top-down view of an exemplary structure after formation of a metal layer and patterned hard mask portions according to an embodiment of the present disclosure.

"FIG. 1B is a vertical cross-sectional view of the exemplary structure along the vertical plane B-B' of FIG. 1A.

"FIG. 2A is a top-down view of the exemplary structure after formation of a dielectric metal-containing compound portions according to an embodiment of the present disclosure.

"FIG. 2B is a vertical cross-sectional view of the exemplary structure along the vertical plane B-B' of FIG. 2A.

"FIG. 3A is a top-down view of the exemplary structure after a pull back of the hard mask portions according to an embodiment of the present disclosure.

"FIG. 3B is a vertical cross-sectional view of the exemplary structure along the vertical plane B-B' of FIG. 3A.

"FIG. 4A is a top-down view of the exemplary structure after formation of trenches through the metal layer according to an embodiment of the present disclosure.

"FIG. 4B is a vertical cross-sectional view of the exemplary structure along the vertical plane B-B' of FIG. 4A.

"FIG. 5A is a top-down view of the exemplary structure after a pull back of the hard mask portions according to an embodiment of the present disclosure.

"FIG. 5B is a vertical cross-sectional view of the exemplary structure along the vertical plane B-B' of FIG. 5A.

"FIG. 6A is a top-down view of the exemplary structure after formation of additional dielectric metal-containing compound portions according to an embodiment of the present disclosure.

"FIG. 6B is a vertical cross-sectional view of the exemplary structure along the vertical plane B-B' of FIG. 6A.

"FIG. 7A is a top-down view of the exemplary structure after a pull back of the hard mask portions according to an embodiment of the present disclosure.

"FIG. 7B is a vertical cross-sectional view of the exemplary structure along the vertical plane B-B' of FIG. 7A.

"FIG. 8A is a top-down view of the exemplary structure after formation of additional trenches through the metal layer according to an embodiment of the present disclosure.

"FIG. 8B is a vertical cross-sectional view of the exemplary structure along the vertical plane B-B' of FIG. 8A.

"FIG. 9A is a top-down view of the exemplary structure after a sequence of a pull back of the hard mask portions, formation of additional dielectric metal-containing compound portions, another pull back of the hard mask portions, and formation of additional trenches according to an embodiment of the present disclosure.

"FIG. 9B is a vertical cross-sectional view of the exemplary structure along the vertical plane B-B' of FIG. 9A.

"FIG. 10A is a top-down view of the exemplary structure after repeatedly performing the sequence of a pull back of the hard mask portions, formation of additional dielectric metal-containing compound portions, another pull back of the hard mask portions, and formation of additional trenches according to an embodiment of the present disclosure.

"FIG. 10B is a vertical cross-sectional view of the exemplary structure along the vertical plane B-B' of FIG. 10A.

"FIG. 11A is a top-down view of the exemplary structure after transfer of the pattern in the metal layer into an underlying material layer by an anisotropic etch according to an embodiment of the present disclosure.

"FIG. 11B is a vertical cross-sectional view of the exemplary structure along the vertical plane B-B' of FIG. 11A.

"FIG. 12A is a top-down view of the exemplary structure after removal of the dielectric metal-containing compound layer and the metal layer according to an embodiment of the present disclosure.

"FIG. 12B is a vertical cross-sectional view of the exemplary structure along the vertical plane B-B' of FIG. 12A.

"FIG. 13 is a vertical cross-sectional view of a variation of the exemplary structure according to an embodiment of the present disclosure."

For additional information on this patent application, see: Tseng, Chiahsun; Horak, David V.; Yeh, Chun-chen; Yin, Yunpeng. Non-Lithographic Line Pattern Formation. Filed July 30, 2012 and posted February 6, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=5471&p=110&f=G&l=50&d=PG01&S1=20140130.PD.&OS=PD/20140130&RS=PD/20140130

Keywords for this news article include: International Business Machines Corporation.

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


For more stories covering the world of technology, please see HispanicBusiness' Tech Channel



Source: Politics & Government Week


Story Tools