Abstract: An SOI substrate (30) comprises a buried oxide film (2), an SOI layer (3) formed on a first region (51) of the surface (2S) of the buried oxide film, and a silicon oxide film (8) formed on a second region (52) of the surface (2S). Formed on the peripheral portion of the SOI layer (3) is a silicon oxide film (6), the side surface (6H) of which is integrally joined to the side surface (8H) of the silicon oxide film (8). The thickness of the peripheral portion of the SOI layer (3) decreases as closer to the end portion (3H) of the SOI layer (3), while the thickness of the silicon oxide film (6) formed on the peripheral portion of the SOI layer (3) increases as closer to the end portion (3H). A gate oxide film (9) is formed on a predetermined region of the surface of the SOI layer (3), and joined to the silicon oxide film (6) at its end portion.

Abstract: To provide a semiconductor device capable of preventing drawbacks from being caused by metal pollution and a method of manufacturing the semiconductor device. A region (NR) and a region (PR) are defined by a trench isolation oxide film (ST21), a polysilicon film (PS21) is selectively provided on the trench isolation oxide film (ST21), a silicon layer (S22) is provided on the polysilicon film (PS21), and a side wall spacer (SW2) is provided on a side surface of the polysilicon film (PS21). The polysilicon film (PS21) is provided in a position corresponding to a top of a PN junction portion JP of a P-type well region (WR11) and an N-type well region (WR12) in an SOI layer 3 across the two well regions.

Abstract: An SOI layer is thinned without a thermal oxidation process. An SOI substrate (10) is immersed in an etching bath filled with an NH3—H2O2—H2O solution to be isotropically etched. This produces a 100-nm thick SOI layer (3) with no crystal defect.

Abstract: An SOI layer is thinned without a thermal oxidation process. An SOI substrate (10) is immersed in an etching bath filled with an NH3—H2O2—H2O solution to be isotropically etched. This produces a 100-mn thick SOI layer (3) with no crystal defect.

Abstract: The invention provides a semiconductor device having the trench-shaped isolator is provided with a portion which is adjacent to the semiconductor element region, of which the width is continuously decreased in the downward direction, and of which the surface is planarized near the semiconductor element region, for relaxing the stress in the silicon layer and being flat the surface of the trench-shaped insulator, and method of manufacturing the same.

Abstract: The invention provides a semiconductor device having the trench-shaped isolator is provided with a portion which is adjacent to the semiconductor element region, of which the width is continuously decreased in the downward direction, and of which the surface is planarized near the semiconductor element region, for relaxing the stress in the silicon layer and being flat the surface of the trench-shaped insulator, and method of manufacturing the same.

Abstract: A semiconductor integrated circuit is formed by MESA isolation of a thin film silicon layer, in which transistor characteristics are free from influence depending on pattern density of transistor forming regions. The thin film silicon layer on an insulating substrate is isolated by MESA isolation, and element forming regions are formed. In the middle part of a large distance between the element forming regions, a LOCOS oxide film is thickly formed, and an oxide film is buried between the LOCOS oxide film and the element forming regions contiguously at the same surface level so that there is no step-like level difference therebetween.

Abstract: A sidewall oxide layer and a sidewall insulation layer are formed to cover the edge portion of an SOI layer. A channel stopper region is formed in the vicinity of the edge portion of the SOI layer. A protruded insulation layer is formed on the channel stopper region. A gate electrode extends from a region over the SOI layer to the protruded insulation layer and the sidewall insulation layer. In this way, reduction in threshold voltage Vth of a parasitic MOS transistor at the edge portion of the SOI layer can be suppressed.

Abstract: At an edge portion of an FS gate electrode (10) beneath a side wall oxide film (106), an FS gate oxide film (101) is thicker. Relative to a surface of a silicon substrate (SB) beneath the FS gate oxide film (101), other surface of the silicon substrate (SB) is retracted. Thus, a MOS transistor with field-shield isolation structure and a method for manufacturing the same can be provided with higher reliability of the gate oxide film.

Abstract: A semiconductor substrate and a method of fabricating a semiconductor device are provided. An oxide film (13) is formed by oxidizing an edge section and a lower major surface of an SOI substrate (10). This oxidizing step is performed in a manner similar to LOCOS (Local Oxide of Silicon) oxidation by using an oxide film (11) exposed on the edge section and lower major surface of the SOI substrate (10) as an underlying oxide film. Then, the thickness of the oxide film (13) is greater than that of the oxide film (11) on the edge section and lower major surface of the SOI substrate (10). The semiconductor substrate prevents particles of dust from being produced at the edge thereof.

Abstract: Formed on an insulator (9) are an N− type semiconductor layer (10) having a partial isolator formed on its surface and a P− type semiconductor layer (20) having a partial isolator formed on its surface. Source/drain (11, 12) being P+ type semiconductor layers are provided on the semiconductor layer (10) to form a PMOS transistor (1). Source/drain (21, 22) being N+ type semiconductor layers are provided on the semiconductor layer (20) to form an NMOS transistor (2). A pn junction (J5) formed by the semiconductor layers (10, 20) is provided in a CMOS transistor (100) made up of the transistors (1, 2). The pn junction (J5) is positioned separately from the partial isolators (41, 42), where the crystal defect is thus very small. Therefore, the leakage current is very low at the pn junction (J5).

Abstract: At an edge portion of an FS gate electrode (10) beneath a side wall oxide film (106), an FS gate oxide film (101) is thicker. Relative to a surface of a silicon substrate (SB) beneath the FS gate oxide film (101), other surface of the silicon substrate (SB) is retracted. Thus, a MOS transistor with field-shield isolation structure and a method for manufacturing the same can be provided with higher reliability of the gate oxide film.

Abstract: FS-isolated fields (10a, 10b). LOCOS-isolated fields (11c, 11d). FS-isolated fields (10e, 10f), LOCOS-isolated field (11g, 11h) and FS-isolated field (10i) are arranged in this order. Thus, a master layout can he provided, where SOI transistors having bodies to be supplied with fixed potential and those having bodies not to be supplied with fixed potential are mixed.

Abstract: On an insulating film a mesa-isolation silicon layer is formed, in which a channel region and source/drain regions ar included. A gate insulating film and a conducting layer as a part of a gate electrode are stacked on the mesa-isolation silicon layer. A sidewall of an insulating material is formed on side surfaces of the mesa-isolation silicon layer, gate insulating film, and conducting layer at an end portion of the channel region of the mesa-isolation silicon layer, and a gate electrode is formed on the conducting layer.

Abstract: According to a method of manufacturing a thin film transistor (TFT), amorphous silicon is formed by ion-implanting either silicon or nitrogen into a region of polysilicon while a region located at the sidewall of a gate electrode is selectively left using the stepped portion of the gate electrode. Then, a heat treatment is applied to convert the amorphous silicon into polysilicon with the remaining polysilicon as a seed crystal. As a result, polysilicon having crystal grains of great grain size can be formed in uniform. Thus, the electric characteristics of a TFT can be improved with no difference in the electric characteristics between each TFT.

Abstract: An SOI substrate (10) has a buried oxide film (31) formed on a silicon substrate (2) and an SOI layer (4) formed on the buried oxide film. The buried oxide film substantially uniformly contains fluorine over the whole area thereof, and is reduced in relative dielectric constant as compared with a silicon oxide film, having a relative dielectric constant of about 3.9, containing no fluorine. The fluorine concentration of the buried oxide film (31) is set to be at any level in the range of 1×1019 to 1×1022 cm−3 substantially over the whole area. Thus provided is a MOS transistor suppressing influence by a DIBL effect and preventing occurrence of current leakage on an edge portion of a channel region resulting from influence by an electric field from an adjacent semiconductor element.

Abstract: A method of fabricating an SOIMOS transistor, isolated by trench isolation, which can prevent a gate oxide film from dielectric breakdown on peripheral edge portions of an SOI layer while preventing formation of parasitic MOS transistors on the peripheral edge portions of the SOI layer under a gate electrode is provided. A nitride film (6) is removed with phosphoric acid of about 160° C. in temperature and thereafter a polysilicon film (5) is removed by isotropic dry etching, thereby leaving a pad oxide film (4) and side wall oxide films (7) in a state enclosed with a deposition oxide film (8). Thereafter the pad oxide film (4), the side wall oxide films (7) and the deposition oxide film (8) are simultaneously removed with hydrofluoric acid.

Abstract: An FS upper nitride film (15) is formed on the upper surface of an FS electrode (5). Therefore, the upper surface of the FS electrode (5) is not exposed even when an FS upper oxide film (41) is partially almost removed in the manufacturing process. Thus, a semiconductor device which prevents degradation in operation characteristics and reliability due to existence of an FS insulating layer can be provided.

Abstract: According to a method of manufacturing a thin film transistor (TFT), amorphous silicon is formed by ion-implanting either silicon or nitrogen into a region of polysilicon while a region located at the sidewall of a gate electrode is selectively left using the stepped portion of the gate electrode. Then, a heat treatment is applied to convert the amorphous silicon into polysilicon with the remaining polysilicon as a seed crystal. As a result, polysilicon having crystal grains of great grain size can be formed in uniform. Thus, the electric characteristics of a TFT can be improved with no difference in the electric characteristics between each TFT.

Abstract: This invention provides a semiconductor device with a SOI structure and a method of manufacturing the same, preventing deterioration in and making improvement in device characteristics. Nitrogen ion implantation into NMOS and PMOS regions (NR, PR) with resists (22b) and (22c) as masks, respectively, introduces nitrogen ions into channel doped layers (31). The subsequent thermal treatment provides a structure with the channel doped layers (31) containing nitrogen having a prescribed concentration distribution in the depth direction.