摘要:
A semiconductor memory, particularly, a dynamic RAM, is provided having a two-cell one-contact memory cell connection structure. A connection portion between memory cells in a silicon substrate of a dynamic RAM, wherein each memory cell has one silicon island enclosed by a trench and provided with two transistor cells within said island, is formed by connecting a polysilicon electrode, enclosing the periphery of the silicon island at the inside of the trench and separated at two portions of the periphery of the silicon island, to the source or drain of one of the two transistor cells of the memory cell. The connection of the polysilicon electrode to the source or drain of the transistor cell of each of two adjacent memory cells can be easily achieved through self aligning by using a fine-trench polysilicon burying method or a selective epitaxial method.
摘要:
A method of fabricating a semiconductor device comprising a step of forming a trench on a semiconductor substrate, a step of positioning the semiconductor substrate in a first position such that the direction of the ion beams is inclined to a plane which is perpendicular to the principal surface of the semiconductor substrate and which is parallel to a first side-wall of the trench, a step of implanting ions into the first side-wall by emitting ion beams onto the first side-wall of the trench of the semiconductor substrate at the first position, a step of rotating the semiconductor substrate about an axis perpendicular to the principal surface thereof to a second position which is different from the first position, a step of implanting ions into a second side-wall by emitting ion beams onto the second side-wall of the trench of the semiconductor substrate at the second position, a step of rotating the semiconductor substrate about the axis to a third position which is different from the first and second positions, a step of implanting ions into a third side-wall by emitting ion beams onto the third side-wall of the trench of the semiconductor substrate at the third position, a step of rotating the semiconductor substrate about the axis to a fourth position which is different from the first, second and third positions, and a step of implanting ions into a fourth side-wall by emitting ion beams onto the fourth side-wall of the trench of the semiconductor substrate at the fourth position.
摘要:
After formation of a silicon Fin part on a silicon substrate, a thin film including an impurity atom which becomes a donor or an acceptor is formed so that a thickness of the thin film formed on the surface of an upper flat portion of the silicon Fin part becomes large relative to a thickness of the thin film formed to the surface of side wall portions of the silicon Fin part. A first diagonal ion implantation from a diagonal upper direction to the thin film is performed and subsequently a second diagonal ion implantation is performed from an opposite diagonal upper direction to the thin film. Recoiling of the impurity atom from the inside of the thin film to the inside of the side wall portions and to the inside of the upper flat portion is realized by performing the first and second diagonal ion implantations.
摘要:
A method of fabricating a semiconductor device comprising a step of forming a trench selectively on a semiconductor substrate, a step of positioning said semiconductor substrate to a first position inclined to a plane vertical to ion beams, a step of injecting ions by emitting ion beams to a side-wall of the trench of the semiconductor substrate at the first position, a step of positioning said semiconductor substrate to a second position which is different from the first position by rotating it, and a step of injecting ions by emitting ion beams to a side-wall of the trench of the semiconductor substrate at the second position.
摘要:
Crystal evaluation apparatus is disclosed which includes a cell region having an anode and a cathode, a reservoir tank for supplying of an aqueous solution for forming an anodic oxide film in the cell region, a reservoir tank for supplying of an aqueous solution for removing the anodic oxide film and a scanning microprobe microscope having a scanning microprobe, installed inside the cell region. A crystal evaluation method is also disclosed which contains anodic oxidation on a semiconductor substrate, removal of an anodic oxide film developed. The semiconductor substrate is observed with a scanning probe microscope having a scanning microprobe. The oxide film is formed on the semiconductor substrate by the anodic oxidation method and then removed by a mixture of hydrofluoric acid and ammonium fluoride. The anodic oxidation method exerts no or little physical impact on the substrate. The hydrofluoric acid and ammonium fluoride mixture removes selectively only the oxide film so that secondary ion implantation defects are exposed to a surface of the substrate. The shape or configuration of the secondary ion implantation defects is observed with an atomic force microscope having a high resolution on the order of nano meter. Therefore, the shape of the defects on the order of nano meter may be observed. In addition, the distribution of impurity concentration over the surface of the substrate may be measured very accurately.
摘要:
An ion implanting method which suppresses defects by changing the shape of the amorphous layer formed by ion injection from that of a conventional device.After forming a mask pattern on a semiconductor wafer, amorphous layers are then formed with sufficient penetration under the mask material by implanting ions at an implant angle greater than or equal to 20 degrees with a dose amount enough for forming amorphous layers. In this large angle ion implanting method, the edge of each amorphous layer becomes dull and, thereby, no voids are formed in a successive heat treatment.
摘要:
An ion implantation method comprising doping a trench sidewall formed in the surface of a semiconductor substrate, with impurities by intermittently rotating step ion implantation carried out in the state that said sidewall is angled with respect to an ion beam, wherein;the amount of ion implantation to said sidewall is made uniform by varying the scanning velocity of the ion beam on the surface of said semiconductor substrate, at the position near to, and the position distant from, the upstream side of the beam applied to a position at which said surface of semiconductor substrate is inclined with respect to the beam.Also disclosed is a method of manufacturing a semiconductor device making use of such an ion implantation method.
摘要:
A semiconductor memory device (DRAM) includes a plurality of island regions, at least one cell transistor disposed on each island region and a cylindrical capacitor surrounding each island region. With such a structure, the capacity of the cell capacitor incorporated into a small space can be increased. Furthermore, a method of fabricating a semiconductor memory device includes a step of forming a groove having a necessary depth in a semiconductor substrate, a step of depositing a membrane having excellent covering characteristics in the groove, a step of etching by using an etching method having a strong anisotropy in the vertical direction while leaving the deposited membrane on a sidewall, and a step of etching the exposed portion of the semiconductor surface deeper in the groove and forming a capacity element and isolation region by using this deep trench.
摘要:
An improved method for fabrication of a super-high density semiconductor device wherein ion implantation is used to eliminate defects or inhibit the occurrence of growth of defects in the semiconductor device. Ions of high concentration are implanted into a monocrystal semiconductor region in which principal elements such as bipolar element and MOS element are formed, by using a mask pattern covering the semiconductor region and at a largely inclined implantation angle equal to or of more than 20 degrees. This provides for formation of amorphous regions 170A, 170B extending sufficiently into areas beneath the ends of the mask. The amorphous regions are recrystallized by heat treatment, thereby inhibiting the growth of a corner defect known as "voids 21" which has often occurred at edges of amorphous regions 170A, 170B in the conventional method. Thus, a device which is less liable to electrical leaks is provided.
摘要:
By symmetrically forming source and drain regions to the gate electrodes, electrically symmetrical transistor characteristics are obtained. After forming the first source and drain regions by large-tilt-angle ion implantation, without a sidewall in the gate electrode or after forming a sidewall shorter than the distance in the lateral direction of the second source and drain regions from the end of the mask for ion implantation, the diffusion of the second source and drain regions in the lateral direction is restricted to the maximum extent by heat treatment for a short time, and then the end of the gate electrode and the end of the second source and drain regions are matched, or their overlap region is formed. As a result, the manufacturing method of the MOS transistor results in both high performance and high reliability.