Abstract:
Disclosed are methods for depositing multilayer ohmic contacts upon a substrate of semiconductor material disposed within a low pressure chamber; such including for example the particular features of upward sputtering of the various metal films including deposition of a thin layer of molybdenum directly on initially formed integral areas of platinum silicide, followed by simultaneous sputtering of platinum with gold utilizing a sputtering cathode composed of platinum and gold, with the addition of hydrogen into an inert sputtering atmosphere to eliminate undesireable formation of oxides. This invention provides improved adhesion of the sputtered metal films to the semiconductor surface and the silicon oxide, and provides the formation of the metal film which is substantially free of pin holes and which has substantially uniform resistivity.
Abstract:
A METHOD AND SYSTEM FOR RF SPUTTERING THIN CONDUCTING AND THIN INSULATING FILMA ON A SEMICONDUCTOR SUBSTRATE USING A FIRST ELECTRODE FOR SUPPORTING A SOURCE MATERIAL AND AN APERTURED SECOND ELECTRODE. THE RF VOLTAGE IS APPLIED ACROSS THE FIRST AND SECOND ELECTRODES. THE SUBSTRATE IS SUPPORTED BY A THIRD ELECTRODE AND EXPOSED TO ATOMS SPUTTERED FROM THE SOURCE WHICH PASS THROUGH THE APERTURED SECOND ELECTRODE. THE THIRD ELECTRODE MAY BE AT THE SAME POTENTIAL AS THE SECOND ELECTRODE, OR AT A DIFFERENT POTENTIAL TO CARRY OUT BIAS SPUTTERING. THE SYSTEM INCLUDES MULTIPLE PAIRS OF FIRST AND SECOND ELECTRODES FOR MULTIPLE FILM DEPOSITION WITHOUT BREADING VACUUM AND A ROTATING THIRD ELECTRODE WHICH MOVES THE SUBSTRATES PAST THE APERTURES IN THE SECOND ELECTRODES DURING SPUTTERING TO ELIMI-
NATE SHADOWING AND TO FURTHER ENHANCE COOLING. A SHUTTER IS PROVIDED TO PREVENT CROSSCONTAMINATION OF THE IDLE SOURCES AND THE FILM BEING DEPOSITED ON THE SUBSTRATE.
Abstract:
Disclosed are methods for depositing multilayer ohmic contacts upon a substrate of semiconductor material disposed within a low pressure chamber; such including for example the particular features of upward sputtering of the various metal films, simultaneous sputtering of platinum with gold utilizing a sputtering cathode composed of platinum and gold, and adding hydrogen into an inert sputtering atmosphere to eliminate undesirable formation of oxides. This invention provides imporved adhesion of the sputtered metal films to the semiconductor surface and the silicon oxide, and provides the formation of the metal film which is substantially free of pin holes and which has substantially uniform resistivity.
Abstract:
Insulated gate field effect transistor circuits utilizing transistors having a self-aligned gate, reduced parasitic capacitance and lower surface step-heights are fabricated with three levels of interconnects. The self-aligned gate transistors are fabricated with the use of a silicon nitride diffusion mask which also serves as an oxidation barrier in the formation of a thick oxide over the source and drain regions. Diffused interconnects are formed simultaneously with the source and drain region diffusions. The silicon nitride is then replaced with a more suitable dielectric, followed by the formation of polycrystalline silicon interconnects to provide source, drain and gate electrodes, and to provide a second level of interconnects which cross over the diffused interconnects at desired locations. An insulating layer is formed over the silicon interconnects and a metallization interconnect pattern, which crosses over the silicon interconnects at various desired locations is then formed to complete the circuit.
Abstract:
There is disclosed a multilevel contact and interconnection system for integrated circuits comprising at least three levels. Ohmically connecting to the semiconductor through an opening in its insulating layer is a first layer of molybdenum. The second layer is of gold and the third of molybdenum. This system is virtually alloyless since the molybdenum does not alloy with the semiconductor material or the gold.
Abstract:
Disclosed is a tungsten ohmic contact and electrical interconnection system for semiconductor devices. Particularly, a system of one or more levels of multilayer metal interconnections for integrated circuits. The multilayer metal interconnections are composed of outer tungsten layers of metal that adhere well to silicon and silicon oxide with an intermediate layer of high conductivity metal. Different levels of multilayer metal interconnections are separated from one another by insulating layers with holes that allow ohmic contacts to be made between different levels. The final or top multilayer metal interconnections can have one adherent metal layer covered by the high conductive metal layer.
Abstract:
A metallization system for semiconductor devices includes a first layer of aluminum a part of which is in ohmic contact with a silicon substrate and devices thereon, the other part of which overlies an insulating layer. A second layer of molybdenum is deposited on the aluminum layer. The aluminum and molybdenum are photoetched into a predetermined pattern which ohmically contacts the silicon and overlies an insulating layer, usually of silicon dioxide. Thereafter a variety of techniques and lead systems can be used. For example, a second layer of insulating material can be applied over the first level aluminum-molybdenum metallization system and the first layer of insulating material. The second level of insulating material can then be selectively etched to expose predetermined portions of the first level lead system. Thereafter, beam leads can be attached to the first level metallization system; or bonding pads can be formed in ohmic contact with the first level metallization system. Alternatively, a second level metallization system can be utilized where it becomes necessary to conductively connect various components on the semiconductor device by lead cross-overs. A third layer of insulating material can then be applied on top of the second level metallization system. After selective etching of the second level insulating material, beam leads, bonding pads or even a third level metallization system can be applied.