International Business Machines Corporation

Edward J Vishnesky

Shaw-Ning Mei

Joseph F Shepard

Manu J Tejwani

Scott R Stiffler

Toshio Mii

Louis L Hsu

Jack Oon Chu

Louis Lu-Chen Hsu

Howard Smith Landis

Bao T Hwang

Senthilkumar Arthanari

John W Andrews

T Howard Shillingford

James M Tyler

Jack C Chu

A method is provided for planarizing a structure such as a shallow trench isolation region on a semiconductor substrate. A semiconductor substrate is provided having raised and lowered regions with substantially vertical and horizontal surfaces. The lowered regions may correspond to trench regions. The upper regions are covered by a masking layer of nitride having a predetermined thickness. Filler material such as non-conformal high density plasma oxide may be deposited over the horizontal surfaces to a thickness terminating within that of the thickness of the nitride layer. The raised regions of the filler material are then selectively removed in a single planarizing step without removing the filler material in the lowered regions using a fixed abrasive hard polishing pad, as opposed to an abrasive slurry.

Shallow trench isolation using non-conformal dielectric and planarizatrion

A method to planarize a semiconductor surface using a Fence Creation and Elimination (FCE) process is described. Shallow recesses on a semiconductor surface are filled with a filling material. The filling material is deposited on the semiconductor surface to a thickness approximately equal to the depth of the shallow recesses. A selectively etchable material is formed on the filling material. A reverse mask (RM) is used to pattern the selectively etchable material to form segments of the selectively etchable material equal to the pattern of the shallow recesses and aligned to the shallow recesses. Exposed filling material is removed followed by the removal of the segments of the selectively etchable material. The remaining filling material in the shallow recesses forms fences which extend above the surface of the semiconductor. The fences are removed resulting in a planar semiconductor surface.

Method to planarize semiconductor surface

A method is provided for planarizing a structure such as a shallow trench isolation region on a semiconductor substrate. A semiconductor substrate is provided having raised and lowered regions with substantially vertical and horizontal surfaces. The lowered regions may correspond to trench regions. Filler material such as non-conformal high density plasma oxide may be deposited over the horizontal surfaces to at least a thickness equal to a predetermined height so as to provide raised and lowered regions of the filler material. The raised regions of the filler material may then be selectively removed without removing the filler material in the lowered regions.

Low cost shallow trench isolation using non-conformal dielectric material

A flash memory cell comprises a substrate having a trench formed below the substrate surface, a vertical bit line or auxiliary gate deposited in the trench below the surface, a drain region formed in the substrate below the bit line, and a split floating gate deposited in the trench below the surface to a depth less than the vertical bit line. The floating gate includes a first vertical portion on one side of the bit line and a second vertical portion on another side of the bit line opposite the first vertical portion, with each portion of the gate being accessed by the bit line. The memory cell further includes a source region formed below the surface spaced apart from and adjacent each of the floating gate portions and a word line or control gate extending over the substrate, bit line and floating gate portions. The vertical bit line and split floating gate portions extend from the substrate surface to the bottom of the trench, and adjacent portions of the bit line and the floating gate portions extend above the substrate surface at substantially the same height.

Flash memory structure with floating gate in vertical trench

A capacitor is provided having a substrate and a first capacitor plate including a lattice mismatched crystalline material is formed over and supported by a surface of the substrate. A layer of insulating material is formed over and supported by the first capacitor plate. A second capacitor plate including a layer of conductive material is formed over and supported by the layer of insulating material.

Method for forming capacitors with roughened single crystal plates

Capacitors with roughened single crystal plates

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Poughkeepsie, NY, United States of America

Edward J Vishnesky