News Column

Patent Issued for Three Dimensional Semiconductor Memory Devices and Methods of Fabricating the Same

June 4, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- Samsung Electronics Co., Ltd. (Suwon-si, Gyeonggi-do, KR) has been issued patent number 8729622, according to news reporting originating out of Alexandria, Virginia, by VerticalNews editors.

The patent's inventors are Moon, Hui-Chang (Yongin-si, KR); Hwang, Sung-Min (Seoul, KR); Lee, Woonkyung (Seongnam-si, KR).

This patent was filed on October 19, 2011 and was published online on May 20, 2014.

From the background information supplied by the inventors, news correspondents obtained the following quote: "Semiconductor devices are very attractive in an electronic industry because of small size, multi-function and/or low fabrication cost thereof. High performance semiconductor devices and/or low cost semiconductor devices have been increasingly demanded with the development of the electronic industry. The semiconductor devices have been more highly integrated in order to meet the above demands."

Supplementing the background information on this patent, VerticalNews reporters also obtained the inventors' summary information for this patent: "Embodiments may be realized by providing a three dimensional semiconductor memory device having a stacked structure including cell gates stacked therein that are insulated from each other and first string selection gates laterally separated from each other, and the first string selection gates are disposed over an uppermost cell gate of the cell gates. The device also includes vertical active patterns extending through the first string selection gates, and each vertical active pattern extends through each of the cell gates stacked under the first string selection gates. The device further includes multi-layered dielectric layers between sidewalls of the vertical active patterns and the cell gates and between the sidewalls of the vertical active patterns and the first string selection gates, at least one first supplement conductive pattern, and the first supplement conductive pattern is in contact with a sidewall of one of the first string selection gates.

"The first supplement conductive pattern may include a metal pattern and a barrier pattern between the metal pattern and the sidewall of the one of the first string selection gates. The sidewall of the one of the first string selection gates may be laterally concave. A top end of the first supplement conductive pattern may be at a level equal to or lower than a top surface of the one of the first string selection gates, and a bottom end of the first supplement conductive pattern may be at a level equal to or higher than a bottom surface of the one of the first string selection gates.

"The device may include a pair of device isolation patterns disposed at opposing sides of the stacked structure. Opposing sidewalls of each of the cell gates may be in contact with respective ones of the pair of device isolation patterns, and the sidewall of the one of the first string selection gates may contact the first supplement conductive pattern and an opposing sidewall of the one of the first string selection gates may contact one of the pair of device isolation patterns.

"The device may include second string selection gates between the first string selection gates and the uppermost cell gate, and at least one second supplement conductive pattern. The second supplement conductive pattern may be in contact with a sidewall of one of the second string selection gates. The vertical active patterns may penetrate the first and second string selection gates, the cell gates may be stacked under the second string selection gates, and the multi-layered dielectric layers may be between the sidewalls of the vertical active patterns and the second string selection gates. A top end of the second supplement conductive pattern may be at a level equal to or lower than a top surface of the one of the second string selection gates, and a bottom end of the second supplement conductive pattern may be at a level equal to or higher than a bottom surface of the one of the second string selection gates. The first and second supplement conductive patterns may be connected to each other and may be insulated from other first and second supplement conductive patterns contacting neighboring ones of the first and second string selection gates.

"Each of the multi-layered dielectric layers may include a tunnel dielectric layer, a charge storage layer, and a blocking dielectric layer. Portions of the multi-layered dielectric layers may extend laterally to cover bottom and top surfaces of the cell gates and the first string selection gates. The stacked structure may include at least one ground selection gate between a substrate and a lowermost cell gate of the cell gates. The vertical active patterns may extend downwardly to penetrate the at least one ground selection gate. The multi-layered dielectric layers may be between the sidewalls of the vertical active patterns and the at least one ground selection gate.

"Embodiments may also be realized by providing a method of fabricating a three dimensional semiconductor memory that includes forming gate patterns and insulating patterns alternately stacked on a substrate, and the gate patterns include a plurality of cell gates and a first preliminary string selection gate on an uppermost cell gate of the cell gates. The method includes forming vertical active patterns penetrating the gate patterns and the insulating patterns, forming multi-layered dielectric layers between sidewalls of the vertical active patterns and the gate patterns, forming a cutting trench penetrating the first preliminary string selection gate and ones of the insulating patterns on the first preliminary string selection gate to form the first string selection gates laterally separated from each other by the cutting trench, and forming first supplement conductive patterns filling the recessed regions, respectively. Inner sidewalls of the first string selection gates are laterally recessed to form recessed regions adjacent to the cutting trench.

"Forming the first supplement conductive patterns may include forming a supplement conductive layer on the substrate, the supplement conductive layer filling the recessed regions, and removing the supplement conductive layer outside the recessed regions. Forming the first supplement conductive patterns may include performing a selective growth process on the inner sidewalls of the first string selection gates exposed by the recessed regions as seed layers to form the first supplement conductive patterns.

"The method may include forming second supplement conductive patterns. The gate patterns may include a second preliminary string selection gate between the first preliminary string selection gate and the uppermost cell gate. Forming the cutting trench may include forming the cutting trench to penetrate the second preliminary string selection gate and another insulating pattern between the first preliminary string selection gate and the second preliminary string selection gate. The second string selection gate may be formed at opposing sides of the cutting trench and inner sidewalls of the second string selection gates may be laterally recessed to form second recessed regions adjacent to the cutting trench. Forming the second supplement conductive patterns may include filling the second recessed regions.

"Forming the first and second supplement conductive patterns may include, after forming the cutting trench, conformally forming a supplement conductive layer filling the recessed regions and the second recessed regions on the substrate, and anisotropically etching the supplement conductive layer until a bottom surface of the cutting trench is exposed to form the first and second supplement conductive patterns. The method may include forming ones of the first and second supplement conductive patterns to fill one of the recessed regions and one of the second recessed regions at one inner sidewall of the cutting trench. The ones of the first and second supplement conductive patterns may be connected to each other. The method may also include forming the ones of the first and second supplement conductive patterns to be separated from other first and second supplement conductive patterns of another inner sidewall of the cutting trench.

"Embodiments may also be realized by providing a three dimensional semiconductor memory device having a stacked structure including cell gates and string selection gates, the cell gates are stacked in a first direction and insulated from each other, and one of the string selection gates are spaced apart from another of the string selection gates in a second direction that intersects the first direction. The device has a cutting trench on the cell gates, the cutting trench is between the one of the string selection gates and the other of the string selection gates. The device also includes first supplement conductive patterns and one of the first supplement conductive patterns is between a sidewall of the one of the string selection gates and the cutting trench and another of the first supplement conductive patterns is between a sidewall of the other of the string selection gates and the cutting trench.

"The first supplement conductive patterns may be separated from each other. The device may further include vertical active patterns, and one vertical active pattern may extend through the one of the string selection gates and each of the cell gates and another vertical active pattern may extend through the other of the string selection gates and each of the cell gates.

"The first supplement conductive patterns may define portions of sidewalls of the cutting trench. The cutting trench may expose an insulating layer above an uppermost cell gate of the cell gates in the stacked structure such that a bottom surface of the cutting trench may be defined by the insulating layer."

For the URL and additional information on this patent, see: Moon, Hui-Chang; Hwang, Sung-Min; Lee, Woonkyung. Three Dimensional Semiconductor Memory Devices and Methods of Fabricating the Same. U.S. Patent Number 8729622, filed October 19, 2011, and published online on May 20, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=78&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=3859&f=G&l=50&co1=AND&d=PTXT&s1=20140520.PD.&OS=ISD/20140520&RS=ISD/20140520

Keywords for this news article include: Semiconductor, Samsung Electronics Co. Ltd..

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


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Source: Electronics Newsweekly


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