Accession Number : ADD012492
Title : Low Noise Polycrystalline Semiconductor Resistors by Hydrogen Passivation.
Descriptive Note : Patent,
Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC
Personal Author(s) : Lee,Joseph Y ; Kriegel,Michael H ; Chuh,Thomas Y
Report Date : 29 Jul 1986
Pagination or Media Count : 4
Abstract : The present invention is a process of fabricating low noise polycrystalline silicon resistors. This process includes steps to passivate the resistors to reduce the l/f noise which is routinely observed in prior art devices. As mentioned above, most theories suggest that the l/f noise originates in the interfaces where there are carrier traps. The process of the present invention includes a step to passivate these interfaces with hydrogen in a unique treatment which serves to demonstratably improve the l/f noise characteristics of polysilicon resistors. The low noise crystalline silicon resistors are fabricated in the following sequence: 1) deposit an appropriate thickness of ploysilicon film on an oxidized wafer, 2) resistor doping of the polysilicon film by ion implantation, 3) heavy doping of the end-contact regions of the polysilicon film by high-dose ion implantation, 4) patterning the polysilicon resistor, 5) oxidation/annealing of the polysilicon resistor, 6) open contacts to the polysilicon resistor, 7) aluminum metallization to form ohmic contacts, 8) a long (e.g. 3 hours) low temperature (e.g. at 375 C) pure hydrogen annealing to passivate the interface states in ploysilicon resistors.
Descriptors : *PATENTS, *HYDROGEN, *ION IMPLANTATION, *WAFERS, *POLYSILICONS, ALUMINUM, METALLIZING, DOPING, ELECTRIC CONTACTS, TRAPS, DOSE RATE, HIGH RATE, LOW TEMPERATURE, ANNEALING, OXIDATION, FILMS, RESISTORS, PURITY, THICKNESS
Subject Categories : Solid State Physics
Distribution Statement : APPROVED FOR PUBLIC RELEASE