Abstract: A static random access memory having a structure that allow two memory cells to use a common complementary bit line. With two memory cells using a common complementary bit line, the number of necessary bit lines will be reduce by one quarter. In other words, one quarter fewer metal lines are required. This has the effect of lowering the packing density of metal lines, or increasing the product yield and the number of memory cells that can be packed within the same wafer area.

Abstract: A method for fabricating a DRAM cell with a vertical pass transistor is provided. The method of the invention includes sequentially forming a drain region, a gate structure, a source region, and a capacitor on a semiconductor substrate in a vertical distribution so that an area used by the drain region is the total area used by the DRAM cell on the substrate. In other world, the gate structure, the source region, and the capacitor are formed above the semiconductor substrate without direct contact.

Abstract: A semiconductor fabrication method is provided for fabricating a shallow-trench isolation (STI) structure with a rounded corner in integrated circuits through a rapid thermal process (RTP). In the fabrication of the STI structure, a sharp corner is often undesirably formed. This sharp corner , if not eliminated, causes the occurrence of a leakage current when the resultant IC device is in operation that significantly degrades the performance of the resultant IC device. To eliminate this sharp corner , an RTP is performed at a temperature of above 1,100.degree. C., which temperature is higher than the glass transition temperature of the substrate, for about 1 to 2 minutes. The result is that the surface of the substrate is oxidized into an sacrificial oxide layer and the sharp corner is deformed into a rounded shape with a larger convex radius of curvature. This allows the problems arising from the existence of the sharp corner to be substantially eliminated.

Abstract: A method for aliging a shallow trench isolation is provided. An aligning mark which is deeper than a prior technique is formed in a provided substrate. A trench is formed and an aligning trench is formed in the position over the aligning mark. A thick oxide layer is deposited on the semiconiductol substrate, in the trench and in the aligning trench. After a portion of the thick oxide layer removed, another portion of the thick oxide layer is removed by etching back. A gate oxide layer is formed on a substrate comprising the trench and the aligning trench. A polysilicon layer with the step-height profile in the position over the aligning mark is formed on the gate oxide layer.

Abstract: A method for fabricating a shallow trench isolation (STI) structure in a semiconductor substrate. A stop layer is formed on the substrate and a first sacrificial layer is formed on the stop layer. The first sacrificial layer and the stop layer are defined to form an opening on the substrate. A conformal second sacrificial layer with rounded corners is formed on the substrate. The second sacrificial layer, the first sacrificial layer, and a portion of the substrate are anisotropically removed to form a trench in the substrate using the stop layer as a removal stop layer. The substrate is over removed using the stop layer as a mask layer so that spacers of the second sacrificial layer are remained on the substrate to cover portions of sidewalls of the stop layer.