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|United States Patent||6,222,788|
|Forbes ,   et al.||April 24, 2001|
Systems and methods are provided for vertical gate transistors in static pass transistor decode circuits. The vertical gate transistors have multiple vertical gates which are edge defined such that only a single transistor is required for multiple logic inputs. Thus a minimal surface area is required for each logic input. The novel decode circuits of the present invention include an address decoder for a memory device. The decode circuit includes a number of address lines and a number of output lines. The address lines and the output lines form an array. A number logic cells that disposed at the intersections of output lines and address lines. According to the teachings of the present invention each logic cell includes a source region and a drain region in a horizontal substrate. A depletion mode channel region separates the source and the drain regions. A number of vertical gates are located above different portions of the depletion mode channel region. At least one of the vertical gates is located above a first portion of the depletion mode channel region and is separated from the channel region by a first thickness insulator material. At least one of the vertical gates is located above a second portion of the channel region and is separated from the channel region by a second thickness insulator material. According to the present invention, there is no source nor drain region associated with each input and the gates have sub-lithographic horizontal dimensions by virtue of being edge defined vertical gates.
|Inventors:||Forbes; Leonard (Corvallis, OR); Ahn; Kie Y. (Chappaqua, NY)|
|Assignee:||Micron Technology, Inc. (Boise, ID)|
|Filed:||May 30, 2000|
|Current U.S. Class:||365/230.06; 257/302; 257/315|
|Intern'l Class:||G11C 008/00|
|Field of Search:||365/230.06,230.02,185.05,185.1 257/314,315,316,317,318,302|
|4673962||Jun., 1987||Chatterjee et al.||257/68.|
|5583360||Dec., 1996||Roth et al.||257/326.|
|5847425||Dec., 1998||Yuan et al.||257/315.|
|5991225||Nov., 1999||Forbes et al.||365/230.|
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