Abstract: A method for fabricating a photodiode is described in which a pad oxide layer and a silicon nitride layer are sequentially formed on a provided substrate. The silicon nitride layer, and the pad oxide layer and the substrate are sequentially patterned to form an opening in the substrate. A spacer is formed on the sidewall of the opening. With the spacer and the silicon nitride layer serving as a mask, the substrate is etched forming a trench in the substrate. An oxide plug is then formed filling the trench and the opening using the conventional shallow trench fabrication method. A P-well region and an N-well region are formed respectively on two sides of the trench.

Abstract: A method of fabricating a shallow trench isolation includes formation of a trench in a substrate. An oxide layer is formed on the substrate to fill the trench. A barrier layer and a coating layer are formed in sequence over the substrate. A first etching step is performed to remove a portion of the coating layer and the oxide layer to at least expose the oxide layer on the mask layer. A second etching step is performed to remove the other portion of the coating layer and the oxide layer until exposing the mask layer. Thus, micro-scratches and defects do not happen and thus the invention prevents the occurrence of bridging effect and short circuits.

Abstract: A chemical-mechanical polishing process for forming a metallic interconnect includes the steps of providing a semiconductor substrate having a first metallic line thereon, and then forming a dielectric layer over the substrate and the first metallic line. Next, a chemical-mechanical polishing method is used to polish the surface of the dielectric layer. Thereafter, a thin cap layer is formed over the polished dielectric layer. The thin cap layer having a thickness of between 1000-3000 .ANG. can be, for example, a silicon dioxide layer, a phosphosilicate glass layer or a silicon-rich oxide layer. The method of forming the cap layer includes depositing silicon oxide using a chemical vapor deposition method with silicane (SiH.sub.4) or tetra-ethyl-ortho-silicate (TEOS) as the main reactive agent. Alternatively, the cap layer can be formed by depositing silicon nitride using a chemical vapor deposition method with silicane or silicon dichlorohydride (SiH.sub.2 Cl.sub.2) as the main reactive agent.

Abstract: A method for manufacturing mixed-mode devices that can eliminate watermarks resulting from the formation of residues at the dead corner space of an inverted trapezium-shaped structure at the upper end of a shallow trench during dual gate-oxide processing operation. This method uses the same chemical processing conditions for etching the oxide layer and the removal of photoresist layer, so that no watermarks remain after the etching and cleaning processes. MOS transistors are formed over the thin gate oxide layer region and the thick gate oxide region are of, two types, each having a different gate oxide layer thickness so that each has a different operating voltage.

Abstract: A method of forming a dual damascene structure includes forming an oxide layer and a mask layer there on, which both have protuberances over the conductive layers. Then a chemical mechanical polishing is performed to remove the protuberances and to form openings. The protuberances are above the conductive layers.

Abstract: A method of forming a via. A substrate having a first conductive layer thereon is provided. An inter-metal dielectric layer is formed over the substrate layer by high density plasma chemical vapor deposition. An etch stop layer is formed on the inter-metal dielectric layer. An oxide layer is formed on the etch stop layer. The oxide layer is defined, so that a shallow opening aligned with the first conductive layer is formed to exposed the inter-metal dielectric layer. The inter-metal dielectric layer is etched away within the shallow opening until the first conductive layer is exposed. The opening is filled with a second conductive layer. The oxide layer is defined by photolithography and etching with a first selectivity, with which the oxide layer has a comparable etching rate to the etch stop layer. The inter-metal dielectric layer is etched with a second selectivity, with which the inter-metal dielectric layer has an etching rate higher than the etch stop layer.

Abstract: A method of making a shallow trench isolation region which has a reduced kink effect at a subthreshold voltage by forming a shallow trench isolation region, including providing a silicon substrate having a front surface and a backside surface. A first pad oxide layer is c formed over the front surface, and a second pad oxide layer is currently formed over the backside surface. A first silicon nitride layer is formed over the first pad oxide layer, and a second silicon nitride layer is concurrently formed over the second pad oxide layer. The first silicon nitride layer, first pad oxide layer, and the silicon substrate are patterned to form a trench. A side-wall oxide layer is formed within the trench, and a first oxide layer is concurrently formed on a surface of the second silicon nitride layer. A second oxide layer is formed over the first silicon nitride layer and fills the trench. The first oxide layer is removed, and a portion of the second oxide layer is removed.

Abstract: A method for forming a double spacer structure comprising the steps of first providing a semiconductor substrate that has a first gate and a second gate already formed thereon, wherein the gate length of the second gate is greater than the gate length of the first gate. Then, a first insulating layer is formed over the substrate and the gates. Next, a photoresist layer is formed over the first insulating layer above the second gate while exposing the first insulating layer above the first gate. Subsequently, a first etching operation is performed to establish a first spacer structure along the sidewalls of the first gate, and then the photoresist layer is removed leaving the first insulating layer over the second gate. Thereafter, a second insulating layer is formed over the substrate, the first gate and the first insulating layer, and then a second etching operation is performed to establish a second spacer structure along the sidewalls of the second gate.

Abstract: A manufacturing method applicable for forming a via connection to the thin film transistor in a SRAM unit which resolves the problems arising from a conventional method for forming a via for linking up the drain of a load transistor with the gate of a driver transistor in a SRAM unit by changing the processing sequence and also by forming a plug instead of a via.

Abstract: A method is provided for use in semiconductor fabrication processes for forming a plurality of gate oxide layers with various predefined thicknesses in mixed-mode or embedded circuits that are formed in a semiconductor substrate. In particular, the gate oxide layers of various predefined thicknesses are formed by means of separated growth, which allows all the gate oxide layers to be each formed in one single step, instead of combining two or more oxide layers as in conventional processes, so that the thicknesses can be more easily controllable to the desired levels. The quality of the thus-formed gate oxide layers can thus be better assured.

Abstract: Different thicknesses of gate oxide can be formed on a single chip in a single oxidation process by selectively implanting nitrogen into the surface of the chip in a pattern corresponding to the desired differences in gate oxide thickness. Implanting nitrogen to a silicon substrate reduces the rate at which oxide grows on the surface. Thus, by implanting different dosages of nitrogen into the surface of the substrate, thicker or thinner oxide layers can be provided. A processing chip with embedded DRAM can then be formed where the logic circuitry has a thin gate oxide and the DRAM circuitry has a thick gate oxide by implanting the higher dosage of nitrogen into the region of the chip where the logic circuits are to be formed. Different gate oxide thicknesses are then provided by exposing both the logic circuitry and the embedded DRAM section to a single thermal oxidation process.

Abstract: A method of making a shallow trench isolation region includes providing a silicon substrate. A pad oxide layer is formed over the silicon substrate. A silicon nitride layer is formed over the pad oxide layer. The silicon nitride layer and the pad oxide layer are patterned, and a trench is thus formed in the silicon substrate. A side-wall oxide layer is formed on a surface of the silicon substrate within the trench. A doped oxide layer is formed over the silicon nitride layer and within the trench. A portion of the doped oxide layer is removed to expose the silicon nitride layer. The silicon nitride layer is removed. The pad oxide layer is removed. A sacrificial oxide layer is formed over the silicon substrate. A well is formed in the silicon substrate. The sacrificial oxide layer is removed. A gate oxide layer is formed over the silicon substrate. A polysilicon layer is formed over the silicon substrate. The polysilicon layer is patterned to form a polysilicon gate.

Abstract: A method of fabricating a metal-oxide semiconductor (MOS) transistor is provided. This method is devised particularly to reduce the level of degradation to the MOS transistor caused by hot carriers. In the fabrication process, a plasma treatment is applied to the wafer to as to cause the forming of a thin layer of silicon nitride on the wafer which covers the gate and the lightly-doped diffusion (LDD) regions on the source/drain regions of the MOS transistor. This thin layer of silicon nitride acts as a barrier which prevents hot carriers from crossing the gate dielectric layer, such that the degradation of the MOS transistor due to hot carriers crossing the gate dielectric layer can be greatly minimized.

Abstract: A method for forming shallow trench isolation without a recessed edge problem is disclosed. The present invention comprises forming a pad oxide layer on a substrate. Next, a silicon nitride layer is formed on the pad oxide, and a sacrificial layer is formed on the silicon nitride layer. A photo-resist layer that defines an active region on the sacrificial layer is applied. Thereafter, the portions of the sacrificial layer, the silicon nitride layer, the pad oxide layer and the substrate are removed to form a trench. Portions of the silicon nitride layer are undercut, and a dielectric layer is formed to fill the trench. The dielectric layer is planarized until the silicon nitride layer is exposed. Finally, the silicon nitride layer and the pad oxide layer are removed.

Abstract: A liquid crystal display having an improved angular distribution for emerging radiation is described, together with a method for manufacturing it. This was achieved by forming patterns, one per pixel, of concentric annuli in one of the orientation layers and radial spokes in the other orientation layer. This guarantees that there is a wide range in the orientations of the twisted nematics, leading to an improved angular distribution for the emerging radiation. The invention is applicable to both monochrome as well as color displays and may also be used as a way to adjust, during manufacturing, the angular distribution of the emerging light.

Abstract: A field effect transistor has been developed with one source and one drain but with two independent active regions. It is shown how a double switching characteristic can be obtained with this structure which is described along with a process for its manufacture.