News Column

Researchers Submit Patent Application, "Mim Capacitor and Fabrication Method", for Approval

June 18, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventor HONG, ZHONGSHAN (Shanghai, CN), filed on September 25, 2013, was made available online on June 5, 2014.

The patent's assignee is Semiconductor Manufacturing International (Shanghai) Corporation.

News editors obtained the following quote from the background information supplied by the inventors: "Capacitor components are often used as passive electronic devices in integrated circuits (IC) such as radio frequency IC, monolithic microwave IC, etc. Common capacitor components include metal-oxide-semiconductor (MOS) capacitors, PN junction capacitors and MIM (metal-insulator-metal) capacitors. In some specific applications, MIM capacitors provide better electrical characteristics than MOS capacitors and PN junction capacitors. MOS capacitors and PN junction capacitors may be limited by their structures, and vacancy layers can be easily formed at the electrodes during operation. This may cause reduction of frequency characteristics. In contrast, MIM capacitors can provide better frequency and temperature characteristics. In semiconductor manufacturing, MIM capacitors can be formed by interlayer metal and copper interconnect processes, which reduces difficulties and complexities for integration in CMOS front-end processes.

"FIG. 1 depicts an MIM capacitor made by a conventional CMOS IC manufacturing process. The MIM capacitor includes a substrate 100, a conductive layer 103 disposed within the substrate 100, and a dielectric layer 101 disposed on the substrate 100. The dielectric layer 101 has an opening exposing the surface of the conductive layer 103. The MIM capacitor further includes a first metal layer 103, an insulating layer 104, and a second metal layer 105. The first metal layer 103 is formed on the bottom and sidewall of the opening and serves as a first electrode plate of the MIM capacitor. The insulating layer 104 is formed on the surface of the first metal layer 103 and serves as a dielectric layer of the MIM capacitor. The second metal layer 105 is formed on the surface of the insulating layer 104 to fill the opening. The second metal layer 105 serves as a second electrode plate of the MIM capacitor.

"During operation of the MIM capacitor, operating voltages are applied only to the conductive layer 103 and the second metal layer 105. However, such MIM capacitor is prone to leakage current during operation, which affects the stability of MIM capacitors."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventor's summary information for this patent application: "According to various embodiments, there is provided a method for forming an MIM capacitor by first forming a dielectric layer over a substrate containing a conductive layer. A groove can be formed through the dielectric layer to expose the conductive layer in the substrate. A first metal layer can be formed on a sidewall surface and a bottom surface of the groove and on a top surface of the dielectric layer. A sacrificial layer can be formed in the groove to expose a portion of the first metal layer that is on the top surface of the dielectric layer and on a top portion of the sidewall surface of the groove. The exposed portion of the first metal layer can be removed to leave a remaining portion in the groove as a first electrode plate of the MIM capacitor. The sacrificial layer can be removed from the groove to expose the first electrode plate. A dielectric material layer can be formed on the first electrode plate, on the top portion of the sidewall surface of the groove, and on the top surface of the dielectric layer. A second metal layer can be formed on the dielectric material layer and a third metal layer can be formed on the second metal layer to fill the groove in the dielectric layer. The third metal layer, the second metal layer, and the dielectric material layer can then be polished using the top surface of the dielectric layer as a stop layer.

"According to various embodiments, there is also provided an MIM capacitor. An exemplary MIM capacitor includes a dielectric layer disposed over a substrate containing a conductive layer. The dielectric layer can include a groove to expose the conductive layer in the substrate. A first metal layer can be disposed on a bottom surface and a bottom portion of a sidewall surface of the groove and can be used as a first electrode plate of the MIM capacitor. A top surface of the first metal layer on the sidewall surface of the groove can be lower than a top surface of the dielectric layer. A dielectric material layer can be disposed on the first metal layer and on a top portion of the sidewall surface of the groove. The dielectric material layer can serve as a dielectric layer of the MIM capacitor. A second metal layer can be disposed on the dielectric material layer; and a third metal layer can be disposed on the second metal layer to fill the groove. The second metal layer and the third metal layer can serve as a second electrode plate of the MIM capacitor.

"Other aspects or embodiments of the present disclosure can be understood by those skilled in the art in light of the description, the claims, and the drawings of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

"FIG. 1 depicts a cross-sectional view of a conventional MIM capacitor;

"FIGS. 2-11 depict cross-sectional views of an exemplary MIM capacitor at various stages during its formation in accordance with various disclosed embodiments; and

"FIG. 12 depicts an exemplary method for forming an MIM capacitor in accordance with various disclosed embodiments."

For additional information on this patent application, see: HONG, ZHONGSHAN. Mim Capacitor and Fabrication Method. Filed September 25, 2013 and posted June 5, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=4851&p=98&f=G&l=50&d=PG01&S1=20140529.PD.&OS=PD/20140529&RS=PD/20140529

Keywords for this news article include: Electronics, Semiconductor Manufacturing International (Shanghai) 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: Electronics Newsweekly


Story Tools






HispanicBusiness.com Facebook Linkedin Twitter RSS Feed Email Alerts & Newsletters