Patents Assigned to Vanguard International Semiconductor Company
  • Patent number: 6136643
    Abstract: A method for making capacitor-over-bit line (COB) DRAM using a self-aligned contact etching technology is achieved. After forming FET gate electrodes, sidewall spacers are formed from a first Si.sub.3 N.sub.4 etch-stop layer, while a portion of the Si.sub.3 N.sub.4 is retained as an etch-stop layer on the source/drain areas. Self-aligned contact openings are etched in a first oxide layer to the source/drain areas, and polysilicon landing plugs are formed in all the self-aligned openings. A second oxide layer is deposited and contact holes are etched to the landing plugs for bit lines. A polycide layer having a cap layer is deposited and patterned to form bit lines. A third Si.sub.3 N.sub.4 etch-stop layer is conformally deposited over the bit lines and patterned to form openings over the landing plugs for the capacitor node contacts while forming Si.sub.3 N.sub.4 sidewall spacers on the bit lines exposed in the openings.
    Type: Grant
    Filed: February 11, 1999
    Date of Patent: October 24, 2000
    Assignee: Vanguard International Semiconductor Company
    Inventors: Erik S. Jeng, Chun-Yao Chen, Ing-Ruey Liaw, Janmye Sung
  • Patent number: 6137301
    Abstract: In the present invention is described the use of an EPROM that is configred in a special way to monitor in situ the applied voltage to semiconductor product in a bun-in test and capture the maximum value of the applied voltage during the test. This technique operates off the threshold shift mechanism in which gate bias induces electrons at the substrate surface which are accelerated by the drain and trapped in the polysilcon gate after the electrons overcome the gate oxide energy barrier. This puts an extra bias on the gate making a threshold voltage shift. The measurement of the threshold voltage shift for a particular period of time will be proportional to the value of the applied voltage. The trapped electrons can be released back to the substrate by use of ultra violet light since the electrons gain energy from the UV light to overcome the gate oxide energy barrier.
    Type: Grant
    Filed: May 11, 1998
    Date of Patent: October 24, 2000
    Assignee: Vanguard International Semiconductor Company
    Inventor: Chung-Zen Chen
  • Patent number: 5759895
    Abstract: A method of forming a high capacitance capacitor which does not require additional integrated circuit chip surface area. A capacitor storage electrode or first capacitor plate is formed from amorphous silicon and attached to a polysilicon stud. Dielectric is removed from the under side of the first capacitor plate. The amorphous silicon is then annealed at low pressure to form hemispherical grain polysilicon on the surface of the amorphous silicon thereby increasing the surface area. In one embodiment polysilicon spacers are used to increase the first capacitor plate surface area. The first capacitor plate is then covered by a conformal dielectric layer and a polysilicon second capacitor plate is formed. The capacitor extends over the active integrated circuit chip area but is above the surface of the chip and thereby does not use additional chip area.
    Type: Grant
    Filed: October 14, 1997
    Date of Patent: June 2, 1998
    Assignee: Vanguard International Semiconductor Company
    Inventor: Horng-Huei Tseng
  • Patent number: 5753557
    Abstract: A method of forming a transistor having silicide contacts to shallow gate, source and drain regions 18 in a substrate 10 is disclosed. The transistor has an extended sidewall spacer that covers an outer top portion of the gate. The extended sidewall spacers of the invention extend the distance (leakage path) between the gate and the source/drain thereby reducing the leakage current. The transistor is provided having a gate electrode 12,14,16 and spaced lightly doped source and drain regions 18. A key part of the invention is that the gate insulating layer 16 is laterally etched forming a gate cap insulating layer 16A which only covers an inner central portion of the gate 14. Next, a dielectric layer 20 is formed over the lightly doped source and drain regions 18 and the gate electrode 12,14,16A . The dielectric layer 20 is then anisotropically etched forming extended sidewall spacers 20A which cover the outer top portion of the gate 14.
    Type: Grant
    Filed: October 7, 1996
    Date of Patent: May 19, 1998
    Assignee: Vanguard International Semiconductor Company
    Inventor: Horng-Huei Tseng
  • Patent number: 5650351
    Abstract: A method of fabricating a capacitor having multiple pillars is presented. The invention uses an oxidized hemispherical grain silicon (HSG-Si) layer as a masking layer, in a series of masking steps, to form pillarets on a storage electrode. The method begins by forming a storage electrode having a connection to an active area on the substrate. Next, a cap insulation layer and a cap polysilicon layer are formed over the storage electrode. The cap polysilicon layer has grains and has grain boundaries between the grains. The cap polysilicon layer is oxidized thus forming a thicker oxide layer at the grain boundaries. The oxide layer is dry etched exposing the cap polysilicon layer and leaves a grain boundary oxide covering the grain boundaries. Next, the exposed cap polysilicon layer is etched using the grain boundary oxide as a mask forming a plurality of cap polysilicon layer pillarets. The grain boundary oxide is then removed.
    Type: Grant
    Filed: January 11, 1996
    Date of Patent: July 22, 1997
    Assignee: Vanguard International Semiconductor Company
    Inventor: Shye-Lin Wu
  • Patent number: 5552334
    Abstract: The present invention provides a method of manufacturing a capacitor for a DRAM which uses one mask to define both the node contact hole and the bottom electrode. This novel one mask method uses lateral etch (e.g., oxygen plasma) to enlarge a first opening (the node contact opening) in the resist layer to define a slightly larger second opening which defines the storage electrode. This method reduces the masking steps used and therefore reduces process costs and increases yields. The process comprises forming an insulation layer and a resist layer having a first opening over an active area. A node contact hole is partially etched through the insulation layer. Next, the first opening is enlarged with an lateral etch to form a second slightly larger opening. A storage electrode hole is formed in the insulation layer with the same dimensions as the second opening and the node contact hole is extended to expose the node contact. The resist layer is removed.
    Type: Grant
    Filed: January 22, 1996
    Date of Patent: September 3, 1996
    Assignee: Vanguard International Semiconductor Company
    Inventor: Horng-Huei Tseng