Abstract: An integrated circuit for locating failure process layers. The circuit has a substrate with a scan chain disposed therein, having scan cells connected to form a series chain. Each connection is formed according to a layout constraint of a minimum dimension provided by design rules for an assigned routing layer. Since the connection in the assigned routing layer is constrained to a minimum, the scan chain is vulnerable to variations in processes relevant to the assigned routing layer. The scan chain makes it easier to locate processes causing low yield rate of the scan chain.

Abstract: An integrated circuit for locating failure process layers. The circuit has a substrate with a scan chain disposed therein, having scan cells connected to form a series chain. Each connection is formed according to a layout constraint of a minimum dimension provided by design rules for an assigned routing layer. Since the connection in the assigned routing layer is constrained to a minimum, the scan chain is vulnerable to variations in processes relevant to the assigned routing layer. The scan chain makes it easier to locate processes causing low yield rate of the scan chain.

Abstract: An integrated circuit for locating failure process layers. The circuit has a substrate with a scan chain disposed therein, having scan cells connected to form a series chain. Each connection is formed according to a layout constraint of a minimum dimension provided by design rules for an assigned routing layer. Since the connection in the assigned routing layer is constrained to a minimum, the scan chain is vulnerable to variations in processes relevant to the assigned routing layer. The scan chain makes it easier to locate processes causing low yield rate of the scan chain.

Abstract: An integrated circuit for locating failure process layers. The circuit has a substrate with a scan chain disposed therein, having scan cells connected to form a series chain. Each connection is formed according to a layout constraint of a minimum dimension provided by design rules for an assigned routing layer. Since the connection in the assigned routing layer is constrained to a minimum, the scan chain is vulnerable to variations in processes relevant to the assigned routing layer. The scan chain makes it easier to locate processes causing low yield rate of the scan chain.

Abstract: A method is provided for forming a split-gate flash memory cell having a shallow trench isolation without the intrusion of a “smiling” gap near the edge of the trench encompassing the first polysilicon layer. This is accomplished by forming two conformal layers lining the interior walls of the trench. An exceptionally thin nitride layer overlying the first conformal oxide layer provides the necessary protection during the oxidation of the first polysilicon layer so as to prevent the “smiling” effect normally encountered in fabricating ultra large scale integrated circuits.

Abstract: A modified nitride spacer and making of the same are disclosed. The modified nitride spacer is formed adjacent a high-temperature oxide (HTO) layer which in turn is formed adjacent the sidewalls of a gate electrode. It is shown that the placement of an intervening oxide layer between the sidewalls of the gate electrode and the nitride spacer, in that order only, provides a significant improvement in charge retention in floating gate memory cells. Also, forming of the spacer from pure, undoped oxide only yields the same favorable results.

Abstract: A modified nitride spacer and making of the same are disclosed. The modified nitride spacer is formed adjacent a high-temperature oxide (HTO) layer which in turn is formed adjacent the sidewalls of a gate electrode. It is shown that the placement of an intervening oxide layer between the sidewalls of the gate electrode and the nitride spacer, in that order only, provides a significant improvement in charge retention in floating gate memory cells. Also, forming of the spacer from pure, undoped oxide only yields the same favorable results.

Abstract: A method is provided for forming a split-gate flash memory cell having a shallow trench isolation without the intrusion of a “smiling” gap near the edge of the trench encompassing the first polysilicon layer. This is accomplished by forming two conformal layers lining the interior walls of the trench. An exceptionally thin nitride layer overlying the first conformal oxide layer provides the necessary protection during the oxidation of the first polysilicon layer so as to prevent the “smiling” effect normally encountered in fabricating ultra large scale integrated circuits.

Abstract: A method is provided for forming a split-gate flash memory cell having a shallow trench isolation without the intrusion of a “smiling” gap near the edge of the trench encompassing the first polysilicon layer. This is accomplished by forming two conformal layers lining the interior walls of the trench. An exceptionally thin nitride layer overlying the first conformal oxide layer provides the necessary protection during the oxidation of the first polysilicon layer so as to prevent the “smiling” effect normally encountered in fabricating ultra large scale integrated circuits.

Abstract: A method for fabricating a single polysilicon, non-volatile memory device, has been developed. The method features the use of a metal structure, comprised to contact an underlying control gate region, located in the semiconductor structure, in addition to providing the upper electrode, for a capacitor structure. The capacitor structure, in addition to the metal structure used as the upper electrode, is also comprised of an underlying capacitor dielectric layer, and an underlying polysilicon floating gate structure, used as the lower electrode of the capacitor structure. The creation of the capacitor structure results in performance increases realized via the additional control gate coupling capacitance, obtained via the novel configuration described in this invention.

Abstract: A method for integrating salicide and high voltage device processes in the fabrication of high and low voltage devices on a single wafer is described. Isolation areas are formed on a semiconductor substrate surrounding and electrically isolating a low voltage device area from a high voltage device area. A gate oxide layer is grown in the device areas. A polysilicon layer is deposited overlying the gate oxide layer and isolation areas. A first photomask is formed over a portion of the high voltage device area wherein the first photomask also completely covers the low voltage device area. The polysilicon layer is etched away where it is not covered by the photomask to form a high voltage device. Ions are implanted to form lightly doped source and drain regions within the semiconductor substrate adjacent to the high voltage device wherein the first photomask protects the polysilicon layer in the low voltage device area from the ions. The first photomask is removed.

Abstract: A method is provided for forming a split-gate flash memory cell having a sharp poly tip which substantially improves the erase speed of the cell. The poly tip is formed without the need for conventional oxidation of the polysilicon floating gate. Instead, the polysilicon layer is etched using a high pressure recipe thereby forming a recess with a sloped profile into the polysilicon layer. The recess is filled with a top-oxide, which in turn serves as a hard mask in etching those portions of the polysilicon year not protected by the top-oxide layer. The edge of the polysilicon layer formed by the sloping walls of the recess forms the sharp poly tip of this invention. The sharp tip does not experience the damage caused by conventional poly oxidation processes and, therefore, provides enhanced erase speed for the split-gate flash memory cell. The invention is also directed to a semiconductor device fabricated by the disclosed method.

Abstract: The contact or via hole etch pattern photomask used in fabrication of integrated circuits is modified to provide a series of grooves or trenches to be etched in the silicon oxide layer simultaneously with the contact or via holes. These trenches, after deposition and planarization of tungsten metal layer, afford regenerated alignment marks with sharply-defined edges even after deposition of a second conductive layer.

Abstract: A novel method is presented to form and planarize an inter-metal-dielectric(IMD) layer of an integrated circuit with two or more levels of interconnection metallurgy. The method utilizes chemical-mechanical-polishing(CMP) followed by reactive-ion-etching(RIE) to first planarize and then etch back a deposited IMD layer. Metal line spacings of less than 1.5 microns produce voids in the IMD even when spin-on-glass(SOG) is used to partially fill the spaces prior to IMD deposition. These voids, which contain organic residues and debris, can produce eruptions of material during several subsequent processing steps. The method of this invention attenuates and de-activates these voids, rendering them completely benign. Since CMP is only used to achieve a planar surface, risks of CMP damage to alignment marks and other features are also reduced.