摘要:
A DRAM array having a DRAM cell employing vertical transistors increases electrical reliability and reduces bitline capacitance by use of an asymmetric structure in the connection between the wordline and the transistor, thereby permitting the use of a wider connection between the wordline and the transistor electrode and using the wordline as an etch stop to protect the transistor gate during the patterning of the wordlines.
摘要:
A DRAM memory cell and process sequence for fabricating a dense (20 or 18 square) layout is fabricated with silicon-on-insulator (SOI) CMOS technology. Specifically, the present invention provides a dense, high-performance SRAM cell replacement that is compatible with existing SOI CMOS technologies. Various gain cell layouts are known in the art. The present invention improves on the state of the art by providing a dense layout that is fabricated with SOI CMOS. In general terms, the memory cell includes a first transistor provided with a gate, a source, and a drain respectively; a second transistor having a first gate, a second gate, a source, and a drain respectively; and a capacitor having a first terminal, wherein the first terminal of said capacitor and the second gate of said second transistor comprise a single entity.
摘要:
An anti-fuse structure that can be programmed at low voltage and current and which potentially consumes very little chip spaces and can be formed interstitially between elements spaced by a minimum lithographic feature size is formed on a composite substrate such as a silicon-on-insulator wafer by etching a contact through an insulator to a support semiconductor layer, preferably in combination with formation of a capacitor-like structure reaching to or into the support layer. The anti-fuse may be programmed either by the selected location of conductor formation and/or damaging a dielectric of the capacitor-like structure. An insulating collar is used to surround a portion of either the conductor or the capacitor-like structure to confine damage to the desired location. Heating effects voltage and noise due to programming currents are effectively isolated to the bulk silicon layer, permitting programming during normal operation of the device. Thus the potential for self-repair without interruption of operation is realized.
摘要:
A method and structure for forming an emitter in a vertical bipolar transistor includes providing a substrate having a collector layer and a base layer over the collector layer, forming a patterning mask over the collector layer, and filling openings in the mask with emitter material in a damascene process. The CMOS/vertical bipolar structure has the collector, base regions, and emitter regions vertically disposed on one another, the collector region having a peak dopant concentration adjacent the inter-substrate isolation oxide.
摘要:
Methods of preparing dual workfunction high-performance support metal oxide semiconductor field effect transistor (MOSFETs)/embedded dynamic random access (EDRAM) arrays are provided. The methods describe herein reduce the number of deep-UV masks used in forming the memory structure, decouple the support and arraying processing steps, provide salicided gates, source/drain regions and bitlines, and provide, in some instances, local interconnects at no additional processing costs. Dual workfunction high-performance support MOSFETs/EDRAM arrays having a gate conductor guard ring and/or local interconnections are also provided.
摘要:
A memory cell structure including a planar semiconductor substrate. A deep trench is in the semiconductor substrate. The deep trench has a plurality of side walls and a bottom. A storage capacitor is at the bottom of the deep trench. A vertical transistor extends down at least one side wall of the deep trench above the storage capacitor. The transistor has a source diffusion extending in the plane of the substrate adjacent the deep trench. An isolation extends down at least one other sidewall of the deep trench opposite the vertical transistor. Shallow trench isolation regions extend along a surface of the substrate in a direction transverse to the sidewall where the vertical transistor extends. A gate conductor extends within the deep trench. A wordline extends over the deep trench and is connected to the gate conductor. A bitline extends above the surface plane of the substrate and has a contact to the source diffusion between the shallow trench isolation regions.
摘要:
Short channel effects in vertical MOSFET transistors are considerably reduced, junction leakage in DRAM cells is reduced and other device parameters are unaffected in a transistor having a vertically asymmetric threshold implant. A preferred embodiment has the peak of the threshold implant moved from the conventional location of midway between source and drain to a point no more than one third of the channel length below the bottom of the source.
摘要:
A method for clearing an isolation collar from a first interior surface of a deep trench at a location above a storage capacitor while leaving the isolation collar at other surfaces of the deep trench. A barrier material is deposited above a node conductor of the storage capacitor. A layer of silicon is deposited over the barrier material. Dopant ions are implanted at an angle into the layer of deposited silicon within the deep trench, thereby leaving the deposited silicon unimplanted along one side of the deep trench. The unimplanted silicon is etched. The isolation collar is removed in locations previously covered by the unimplanted silicon, leaving the isolation collar in locations covered by the implanted silicon.
摘要:
An ultra-scalable hybrid memory cell having a low junction leakage and a process of fabricating the same are provided. The ultra-scalable hybrid memory cell contains a conductive connection to the body region therefore avoiding isolation of the P-well due to cut-off by the buried strap outdiffusion region. The ultra-scalable hybrid memory cell avoids the above by using a shallower than normal isolation region that allows the P-well to remain connected to the body of the memory cell.
摘要:
An improved process for making a vertical MOSFET structure comprising: A method of forming a semiconductor memory cell array structure comprising: providing a vertical MOSFET DRAM cell structure having a deposited gate conductor layer planarized to a top surface of a trench top oxide on the overlying silicon substrate; forming a recess in the gate conductor layer below the top surface of the silicon substrate; implanting N-type dopant species through the recess at an angle to form doping pockets in the array P-well; depositing an oxide layer into the recess and etching said oxide layer to form spacers on sidewalls of the recess; depositing a gate conductor material into said recess and planarizing said gate conductor to said top surface of the trench top oxide.