摘要:
Reduced soft errors in charge-sensitive circuit elements such as volatile memory cells 200 occur by using boron-11 to the exclusion of boron-10 or essentially free of boron-10 in borosilicate glass 230, 240 deposited on the substrate 206 directly over the arrays of memory cells. Boron-10 exhibits a high likelihood of fission to release a 1.47 MeV alpha particle upon capture of a naturally occurring cosmic ray neutron. This capture occurs frequently in boron-10 because of its high neutron capture cross-section. Boron-11 does not fission.
摘要:
A heavily-doped semiconductor region and a channel stopper region, which are disposed under a memory cell in a memory cell region, are simultaneously formed after formation of a field insulator film, thereby preventing the channel stopper region from oozing out into the channel region, and thus obtaining a semiconductor memory device which is resistant to .alpha.-rays and therefore free from soft errors caused by .alpha.-rays. Also disclosed is a method of producing said semiconductor memory device.
摘要:
According to this invention, an oxide film is formed on a semiconductor substrate, a metallic boron film or a film containing at least one selected from the group consisting of boron, phosphorus, and arsenic is deposited on the surface of the resultant structure. At least one selected from the group consisting of boron, phosphorus, and arsenic is doped from the metallic boron film or the film containing at least one selected from the group consisting of boron, phosphorus, and arsenic to the oxide film by diffusion without diffusing into the semiconductor substrate. Thus, a semiconductor device having good radiation resistance can be obtained.
摘要:
A method is provided for use with an integrated circuit which includes a npn bipolar transistor on which a variable thickness oxide layer has been formed, the method for improving the radiation hardness of the transistor comprising the steps of: removing the variable thickness oxide layer; and forming a new oxide layer on the transistor, the new oxide layer having less overall volume than the removed variable thickness oxide layer.
摘要:
A technique for forming high-value, inter-nodal, polysilicon coupling resistors using self-aligned silicidation and local interconnect in a double polysilicon process. In an SRAM memory, the technique may be utilized to interconnect the gates of each CMOS invertor to created radiation-hardened cells. Process flow is conventional through gate formation, with transistor gates being patterned from a first polysilicon (poly-1) layer. The transistors which will form each invertor are constructed on distinct active areas. The gate of each invertor transistor extends beyond an edge of the field oxide region, such that an end portion of each gate is superjacent different portions of a single field oxide region. These gate end portions are separated by an expanse of exposed field oxide. The process then departs from convention with a blanket silicon nitride deposition, followed by blanket deposition of a second polysilicon (poly-2) layer. The poly-2 layer is then doped to a desired resistance, then patterned to create a resistive element for the local interconnect. Each invertor gate is connected to the resistive element during the normal flow of the local interconnect process. Preservation of the high resistance of the resistive element is maintained by means of a silicide-isolation oxide film which is created on all but the ends of the resistive element where interconnection to the invertor gates is made. By decoupling the function of the poly-1 and poly-2 layers, the problem of grain-boundary-assisted diffusion between heavily-doped and lightly-doped regions of a contiguous single-poly strip is eliminated. Hence, standard phosphine doping may be used for the poly-1 layer and blanket doping may be used for the poly-2 layer.
摘要:
The field oxide surrounding an NMOS device or the field oxide around the NMOS device and between the NMOS and PMOS devices in CMOS is split or notched to make at least one thin field oxide region under which a degenerative P+ region is formed in the substrate to increase threshold voltages of the undesired field oxide FET.
摘要:
A silicon-over-insulator transistor is provided having a semiconductor mesa (40) overlying a buried oxide (42). Insulating regions (50) are formed at the sides of the semiconductor mesa (40). An oxidizable layer (56) is formed over the mesa's insulating region (46). This oxidizable layer (56) is then anisotropically etched, resulting in oxidizable sidewalls (60). An optional foot (70) may be formed at the bottom edge of the oxidizable sidewalls (76). These oxidizable sidewalls (76) are then oxidized, resulting in a pure oxide sidewall (64). The gate (66) is then formed over the pure oxide sidewalls (64) and a gate oxide (62).
摘要:
The invention comprises an improved bipolar memory device having enhanced protection against the effects of alpha particles comprising at least one memory cell having a buried layer forming at least a portion of the collector of one of the transistors in the memory cell, said buried layer being located sufficiently close to a base layer in only the memory portion of the device to provide a sufficiently high capacitance between said buried layer and said base layer to prevent the occurrence of a soft error caused by an alpha particle striking the structure without interfering with the speed of the device.
摘要:
Integrated circuits with vertical isolated trenches are radiation hardened by providing vertical gate segments, preferably, of doped polycrystalline silicon, in the trenches and connected at the bottom of the trenches to a region of the same conductivity type. The surface devices may be complementary and the vertical gates may also be complementarily doped. A method of fabrication is described for a single crystal wafer, as well as SOI.
摘要:
A method of forming silicon integrated circuits offers radiation resistance together with a high degree of planarity, including a thin field oxide together with a set of conductive plates over the field region combine to suppress the formation of parasitic transistors. In one embodiment, a silicon substrate is etched to form trenches and is then covered with a thin barrier layer, (410) of high quality thermal oxide. A polysilicon layer (423) is next conformally deposited and planarized until the barrier layer (410) is exposed, followed by an oxidation step for isolation or gate oxide formation.