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Patent Issued for Method for Fabricating Contact Electrode and Semiconductor Device

August 27, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- A patent by the inventors Zhu, Huilong (Poughkeepsie, NY); Yin, Haizhou (Poughkeepsie, NY); Luo, Zhijiong (Poughkeepsie, NY), filed on February 24, 2011, was published online on August 12, 2014, according to news reporting originating from Alexandria, Virginia, by VerticalNews correspondents.

Patent number 8803208 is assigned to Institute of Microelectronics, Chinese Academy of Sciences (Beijing, CN).

The following quote was obtained by the news editors from the background information supplied by the inventors: "With the continuous scaling of semiconductor devices, the size of a contact for source/drain is shrinking accordingly. In this case, the contact resistance between the contact and the source/drain may have a trend of becoming greater. The increase of the contact resistance will cause a decline of performances of the semiconductor device."

In addition to the background information obtained for this patent, VerticalNews journalists also obtained the inventors' summary information for this patent: "Considering the above defects in conventional fabrication processes, the present invention provides a method for fabricating a contact, which can reduce the contact resistance by increasing the contact area between the contact and the source/drain. The contact fabricated according to the present invention may have an enlarged end in contact with the source/drain. According to the process characteristics of the present invention, the enlarged end may have a diamondoid cross section. Further, the present invention provides a semiconductor device containing the contact fabricated by the afore-mentioned method for fabricating a contact.

"According to a first aspect of the present invention, a semiconductor device is provided. The semiconductor device comprises: a substrate; a gate, which is formed on the substrate; a source and a drain, which are located on opposite sides of the gate, respectively; a contact, which is contacted with the source and/or the drain, wherein the contact has an increased end part on an end of the contact which is contacted with the source and/or the drain.

"Preferably, the source includes a source in-situ doped layer formed inside the substrate and a raised source layer on the source in-situ doped layer, and the drain includes a drain in-situ doped layer formed inside the substrate and a raised drain layer on the drain in-situ doped layer.

"Preferably, the increased end part of the contact is located on the raised source layer or the raised drain layer.

"Preferably, the increased end part of the contact is located on the raised source layer and the source in-situ doped layer; and/or the increased end part of the contact is located on the raised drain layer or the drain in-situ doped layer.

"Preferably, the contact is formed by a strain contact material.

"Preferably, the substrate is a Si substrate, a crystal face orientation of the Si substrate's surface being , the raised source layer and/or the raised drain layer being formed by growing extendedly along the crystal face orientation of the Si substrate's surface, the increased end part being formed by a wet etching.

"Preferably, the substrate is a Si substrate, a crystal face orientation of the Si substrate's surface being , the raised source layer and/or the raised drain layer being formed by growing extendedly along the crystal face orientation of the Si substrate's surface, a sidewall of the increased end part being in parallel with the crystal face {111} of Si crystal.

"According to a second aspect of the present invention, a method of fabricating a contact is provided. The method comprises steps of: forming a contact hole on a semiconductor device structure, the semiconductor device structure comprising a gate, a source and a drain, a bottom of the contact hole exposing the source and/or the drain; etching the source and/or the drain exposed at the bottom of the contact hole, so as to form a contact hole whose bottom is increased; and filling the contact hole whose bottom is enlarged with the contact material, in order to form a contact contacted with the source and/or the drain, so that the contact has an increased end part on an end of the contact contacted with the source and/or the drain.

"Preferably, the source includes a source in-situ doped layer formed inside the substrate and a raised source layer on the source in-situ doped layer, and the drain includes a drain in-situ doped layer formed inside the substrate and a raised drain layer on the drain in-situ doped layer.

"Preferably, in the etching step, only the source in-situ doped layer and/or the drain in-situ doped layer are etched.

"Preferably, in the etching step, the source in-situ doped layer and the raised source layer are etched, and/or the drain in-situ doped layer and the raised drain layer are etched.

"Preferably, the contact material is a strain contact material.

"Preferably, the substrate is a Si substrate, a crystal face orientation of the Si substrate's surface being , the raised source layer and/or the raised drain layer being formed by growing extendedly along the crystal face orientation of the Si substrate's surface, the increased end part being formed by a wet etching.

"Preferably, the substrate is a Si substrate, a crystal face orientation of the Si substrate's surface being , the raised source layer and/or the raised drain layer being formed by growing extendedly along the crystal face orientation of the Si substrate's surface, a sidewall of the increased end part being in parallel with the crystal face {111} of Si crystal.

"In the present invention, since the contact area on the interface between the contact and the source/drain is increased, the contact resistance can be reduced. Thus, the performances of the semiconductor device can be guaranteed or improved."

URL and more information on this patent, see: Zhu, Huilong; Yin, Haizhou; Luo, Zhijiong. Method for Fabricating Contact Electrode and Semiconductor Device. U.S. Patent Number 8803208, filed February 24, 2011, and published online on August 12, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8803208.PN.&OS=PN/8803208RS=PN/8803208

Keywords for this news article include: Semiconductor, Institute of Microelectronics Chinese Academy of Sciences.

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Source: Electronics Newsweekly


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