Other

Cfm Technologies Limited Partnership

Cfm Technologies Research Associates

Cfm Technologies, Inc.

Christopher F McConnell

Alan E Walter

Object surfaces such as semiconductor wafers which are suspended in a rinsing fluid may be dried by replacing the rinsing fluid, such as water, with a drying vapor by directly displacing the water from the surfaces at such a rate that substantially no liquid droplets are left on the surfaces after replacement of the water with drying vapor. Preferably, the drying vapor is miscible with water and forms a minimum-boiling azeotrope with water, such as isopropanol. The drying vapor is then purged with a stream of dry, inert, noncondensable gas such as nitrogen. A vaporizer with automatic refill mechanism produces saturated drying vapor which may then be flashed to a superheated vapor prior to contacting the surfaces, which preferably are at the same temperature as the vapor. Preferably, no liquid is removed by evaporation, and the drying takes place in an enclosed, hydraulically full system which does not require movement or handling of the surfaces between rinsing and drying steps.

Apparatus for rinsing and drying surfaces

Contamination of wafers is reduced by an enclosed full-flow method and apparatus for the cleaning and other wet processing of semiconductor wafers. Process fluids flow sequentially and continuously past the wafers such that the processing does not require movement or operator handling of the wafers between processing steps. The vessel containing the wafers is hydraulically full during each process step. Wafers may be cleaned using a hot corrosive fluid, such as sulfuric acid; rinsed using high purity water at high flow rates; and dried using a drying fluid such as isopropanol. In addition, chemical reagents such as dilute hydrofluoric acid or hydrogen peroxide may be precisely mixed in situ and applied to the wafer surface for a precisely controlled period, by injecting concentrated reagent into rinse water purified by multipass filtration.

Apparatus for treating wafers with process fluids

Object surfaces such as semiconductor wafers which are suspended in a rinsing fluid may be dried by replacing the rinsing fluid, such as water, with a drying vapor by directly displacing the water from the surfaces at such a rate that substantially no liquid droplets are left on the surfaces after replacement of the water with drying vapor. Preferably, the drying vapor is miscible with water and forms a minimum-boiling azeotrope with water, such as isopropanol. The drying vapor is then purged with a stream of dry, inert, non-condensable gas such as nitrogen. A vaporizer with automatic refill mechanism produces saturated drying vapor which may then be flashed to a superheated vapor prior to contacting the surfaces, which preferably are at the same temperature as the vapor. Preferably, no liquid is removed by evaporation, and the drying takes place in an enclosed, hydraulically full system which does not require movement or handling of the surfaces between rinsing and drying steps.

Process and apparatus for drying surfaces

A system for the fluid treatment of semiconductor wafers includes a treatment vessel having opposed first and second ports, and means for holding wafers in a flow path therebetween. A flow segment comprising in sequence, a first vent, a first valve, an inlet, a second valve and a second vent extends between the first and the second port so as to constitute, together with the vessel, a closed fluid loop. A fluid delivery system for the delivery of a sequence of high purity treatment fluids to a treatment vessel includes a measuring tank having opposed ports and configured for plug flow between the ports, and a metering pump having its inlet connected to a said port for withdrawing metered amounts of fluid from the tank. A plurality of reservoirs of treatment fluid are each connected via a respective associated valve to one of the said ports. The tank is maintained hydraulically full, so that actuating the pump to withdraw a metered volume of fluid from the tank, and opening a valve associated with a selected treatment fluid draws the metered volume of the selected treatment fluid into the tank. Passive or non-mechanical means is provided for delivering the contents of the tank to a treatment vessel. A mixing tank may be provided, between the measuring tank and the treatment vessel. Mixing may be accomplished by bubbling a gas through the fluid held in the mixing tank.

Method and system for fluid treatment of semiconductor wafers

Disclosed is apparatus for treating semiconductor wafers with fluids. The device comprises one or more vessels having lateral walls defining open ends. The vessels are arranged serially, and the open ends are engaged with a treatment fluid inlet and a treatment fluid outlet. Wafers or a wafer carrier are introduced into the vessels for treatment. The vessels are constructed of material that is inert to the treatment fluids and designed to minimize creation of eddy currents and fluid traps. Hydraulically full fluid flow through the vessel uniformly contacts the wafers with the fluid and results in improved and more reproducible prediffusion cleaning, rinsing, etc.

Vessel and system for treating wafers with fluids

A method for the fluid treatment of semiconductor wafers includes a treatment vessel having opposed first and second ports, and means for holding wafers in a flow path therebetween. A flow segment comprising in sequence, a first vent, a first valve, an inlet, a second valve and a second vent extends between the first and the second port so as to constitute, together with the vessel, a closed fluid loop. Preferably, the first and second ports are top and bottom ports, with a flow path extending vertically therebetween. The loop is maintained hydraulically full, whereby filling the vessel with a treatment fluid at the inlet, flushes a preceding treatment fluid from the system. A sequence of treatment fluids of differing densities may be provided at the inlet, and a vent and a valve are controlled to fill the loop from the bottom, in the event the treatment fluid is denser than the preceding fluid, or from the top, in the event the fluid is lighter than the preceding fluid. A circulation pump recirculates fluid within the loop. In another aspect, a fluid delivery system for the delivery of a sequence of high purity treatment fluids to a treatment vessel includes a measuring tank having opposed ports and configured for plug flow between the ports, and a metering pump having its inlet connected to a said port for withdrawing metered amounts of fluid from the tank. A plurality of reservoirs of treatment fluid are each connected via a respective associated valve to one of the said ports. The tank is maintained hydraulically full, so that actuating the pump to withdraw a metered volume of fluid from the tank, and opening a valve associated with a selected treatment fluid draws the metered volume of the selected treatment fluid into the tank. Passive or non-mechanical means is provided for delivering the contents of the tank to a treatment vessel. In a preferred embodiment, the opposed tank ports are top and bottom ports, and the treatment fluids are fluids of differing densities, with the fluids of lesser density each connected via an associated valve to the top port, and the fluids of greater density each connected via an associated valve to the bottom port, minimizing convective mixing during metered filling. A mixing tank may be provided, between the measuring tank and the treatment vessel. Mixing may be accomplished by bubbling a gas through the fluid held in the mixing tank. Methods according to the invention for cleaning semiconductor wafers are disclosed.

Contamination of wafers is reduced by an enclosed full-flow method and apparatus for the cleaning and other wet processing of semiconductor wafers. Process fluids flow sequentially and continuously past the wafers such that the processing does not require movement or operator handling of the wafers between processing steps. The vessel containing the wafers is hydraulically full during each process step. Wafers may be cleaned using a hot corrosive fluid, such as sulfuric acid; rinsed using high purity water at high flow rates; and dried using a drying fluid such an isopropanol. In addition, chemical reagents such as dilute hydrofluoric acid or hydrogen peroxide may be precisely mixed in situ and applied to the wafer surface for a precisely controlled period, by injecting concentrated reagent into rinse water purified by multipass filtration.

Process and apparatus for treating wafers with process fluids

Disclosed is apparatus for treating semiconductor wafers with fluids. The device comprises a plurality of vessel segments having lateral walls for enclosing the wafers defining open ends. Sealing structure is provided at the ends so that the segments may be serially nested together and engaged with a fluid inlet and a fluid outlet in a wafer treatment fluid flow line. The vessel segments are constructed of material that is inert to the treatment fluids and designed to minimize creation of eddy currents and fluid traps. Fluid flowing through the vessel uniformly contacts the wafers and results in improved and more reproducible pre-diffusion cleaning, rinsing, etc.

Method of treating wafers with fluid

An improved apparatus for enclosed flow-line semiconductor wafer treatment includes a wafer-containing vessel and a mechanism for imparting plug-flow to a treatment fluid flowing into the vessel. One plug-flow imparting mechanism includes a flow-expansion input element and a fixed helical flow-diverting surface. Another mechanism incorporates a rotating flow diverting surface.

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Gulph Mills, PA, United States of America

Christopher F McConnell