Renesas Technology Corp.

Hitachi, Ltd.

Kenji Kanamitsu

Norio Suzuki

Norio Ishitsuka

Keiichi Haraguchi

Masataka Kato

Kouzou Watanabe

Shuji Ikeda

Hideo Miura

Tetsuo Adachi

Kozo Watanabe

Yasuko Yoshida

Naohiro Hosoda

Takashi Moriyama

Takashi Kobayashi

Yoshitaka Sasago

Yoshihiro Ikeda

Tsuyoshi Arigane

A semiconductor integrated circuit device and a method of manufacturing the same. The surface of a substrate of an active region surrounded by an element isolation trench is horizontally flat in the center portion of the active region but falls toward the side wall of the element isolation trench in the shoulder portion of the active region. This inclined surface contains two inclined surfaces having different inclination angles. The first inclined surface near the center portion of the active region is relatively steep and the second inclined surface near the side wall of the element isolation trench is gentler than the first inclined surface. The surface of the substrate in the shoulder portion of the active region is wholly rounded and has no angular portion.

Method of manufacturing a semiconductor integrated circuit device having a trench

The object of the present invention is to provide a new nonvolatile semiconductor memory device and its manufacturing method for the purpose of miniaturizing a virtual grounding type memory cell based on a three-layer polysilicon gate, enhancing the performance, and boosting the yield. In a memory cell according to the present invention, a floating gate's two end faces perpendicular to a word line and channel are partly placed over the top of a third gate via a dielectric film. The present invention can reduce the memory cell area of a nonvolatile semiconductor memory device, increase the operating speed, and enhances the yield.

Miniaturized virtual grounding nonvolatile semiconductor memory device and manufacturing method thereof

A reduction in size nonvolatile semiconductors for use in a memory device and an increase in the capacity thereof are promoted. Each memory cell of a flash memory is provided with a field effect transistor having a first gate insulator film formed on a p-type well, a selector gate which is formed on the first insulator film and has side faces and a top face covered with a silicon oxide film (first insular film), floating gates which are formed in a side-wall form on both sides of the selector gate and which are electrically isolated from the selector gate through the silicon oxide film, a second gate insulator film formed to cover the silicon oxide film and the surface of each of the floating gates, and a control gate formed over the second gate insulator film.

Nonvolatile semiconductor memory device and a method of the same

A method of manufacturing a semiconductor device for preventing dielectric breakdown of gate electrodes attributable to needle-like protrusions caused inside a trench in the step of forming element isolation trench in which includes forming a silicon oxide film over a silicon nitride film as an etching mask for forming element isolation trenches, then cleaning the surface of a substrate with a hydrofluoric acid etching solution to lift off obstacles deposited over the surface of the silicon oxide film, before the step of patterning the silicon nitride film by using as a mask a photoresist film provided with an anti-reflection film therebelow.

Method of manufacturing a trench isolation region in a semiconductor device

An AND flash memory of the type wherein a memory cell is constituted of n-type semiconductor regions (a source and a drain) formed in a p-type well of a semiconductor substrate and three gates (including a floating gate, a control gate and a selective gate) is manufactured. In the manufacture, arsenic (As) is introduced into a p-type well in the vicinity of one of side walls of the selective gate to form n-type semiconductor regions (a source and a drain). Thereafter, to cope with a drain disturb problem, the substrate is thermally treated by use of an ISSG (In-Situ Steam Generation) oxidation method so that a first gate, insulating film disposed in the vicinity of one of side walls, at which the n-type semiconductor regions have been formed, is formed thick.

Method of manufacturing a nonvolatile semiconductor memory device

A non-volatile semiconductor memory device provides for higher integration by reducing the area of occupation of direct peripheral circuits, in which the memory cell of an AND type flash memory includes a selection gate, a float gate, a control gate that functions as a word line, and an n-type semiconductor region (source, drain) that functions as a local bit line. A pair of local bit lines adjacent to each other in a memory mat are connected with one global bit line at one end in the direction of the column of the memory mat, and a selection MOS transistor, formed by one enhancement type MOS transistor and one depletion type MOS transistor; is connected in series with each of the pair of local bit lines. One of the local bit lines is selected by turning the selection MOS transistor on/off.

Nonvolatile semiconductor memory device

A semiconductor device free from electric failure in transistors at upper trench edges can be produced by a simplified process comprising basic steps of forming a pad oxide film on the circuit-forming side of a semiconductor substrate; forming an oxidation prevention film on the pad oxide film; removing the oxidation presention film and the pad oxide film at a desired position, thereby exposing the surface of the semiconductor substrate; horizontally recessing the pad oxide film, etching the exposed surface of the semiconductor substrate by isotropic etching; forming a trench to a desired depth, using the oxidation prevention film as a mask; horizontally recessing the pad oxide film; oxidizing the trench formed in the semiconductor substrate; embedding an embedding isolation film in the oxidized trench; removing the embedding isolation film formed on the oxidation prevention film; removing the oxidation prevention film formed on the circuit-forming side of the semiconductor substrate; and removing the pad oxide film formed on the circuit-forming side of the semiconductor substrate, where round upper trench edges with a curvature can be obtained, if necessary, by conducting isotropic etching of exposed surface of the semiconductor substrate and horizontally recessing of the pad oxide film before the oxidation of the trench, whereby only one oxidation step is required.

Process for producing semiconductor device and semiconductor device produced thereby

A semiconductor device and process of forming the device are described. The process includes forming a pad oxide film on the circuit-forming side of a semiconductor substrate; forming an oxidation prevention film on the pad oxide film; removing the oxidation prevention film and the pad oxide film at a desired position, thereby exposing the surface of the semiconductor substrate; horizontally recessing the pad oxide film; etching the exposed surface of the semiconductor substrate by isotropic etching; forming a trench to a desired depth, using the oxidation prevention film as a mask; horizontally recessing the pad oxide film; and oxidizing the trench formed in the semiconductor substrate. The produced device has round upper trench edges obtained by conducting isotropic etching of the exposed surface of the semiconductor substrate and horizontally recessing of the pad oxide film before the oxidation of the trench, whereby only one oxidation step is required.

Growing community of inventors

Hitachinaka, Japan

Kenji Kanamitsu