PROCESSING FOR BONDING TWO SUBSTRATES
The invention relates to a method for bonding two substrates, in particular two semiconductor substrates which, in order to be able to improve the reliability of the process, provides the step of providing a gaseous flow over the bonding surfaces of the substrates The invention also relates to a corresponding bonding equipment
1 .- 15 . (canceled)
16 . A method for forming a composite substrate which comprises:
providing two substrates with bonding surfaces;
providing a flow of a gas over the bonding surfaces of the substrates; and
bonding the substrates together to form the composite substrate;
wherein the flow of gas is provided between the two substrates until the bonding surfaces come into contact.
17 . The method of claim 16 , wherein the flow of gas is a laminar flow.
18 . The method of claim 16 , wherein the flow of gas is provided in a direction that is essentially parallel to the bonding surfaces of the substrates.
19 . The method of claim 16 , wherein the flow of gas is provided at a temperature of from room temperature to 100° C.
20 . The method of claim 16 , which further comprises providing a heat treatment of one or both substrates and providing the flow of gas during the heat treatment.
21 . The method of claim 16 , which further comprises heating the gas such that a heat treatment of one or both the substrates is at least partially carried out using heat from the heated flow of gas.
22 . The method of claim 21 , wherein the heat treatment of both substrates is completely carried out using heat from the heated flow of gas.
23 . The method of claim 16 , wherein the gas has a thermal conductivity of greater than 10×10 −3 W/m-K.
24 . The method of claim 16 , wherein the gas comprises nitrogen or argon.
25 . The method of claim 16 , wherein the gas comprises a mixture or argon with hydrogen, chlorine or fluorine.
26 . The method of claim 16 , wherein the flow of gas is carried out over a time period of a few seconds to several minutes.
27 . The method of claim 16 , wherein the flow of gas is provided in an oxidizing atmosphere.
28 . The method of claim 27 , wherein the oxidizing atmosphere comprises air or 20% oxygen in nitrogen
29 . The method of claim 16 , wherein the flow of gas is provided in a dry atmosphere with a low humidity rate.
30 . Equipment for bonding two substrates together to form a composite substrate comprising means for bonding the substrates together and means to provide a laminar flow of gas between the two substrates at least up until the time that the substrate surfaces contact each other for bonding.
31 . The equipment of claim 30 , wherein the means to provide a flow of gas comprises a ventilation system having one or more gas inlets.
32 . The equipment of claim 30 , wherein the means to provide a flow of gas comprises an aspiration system having one or more gas inlets.
33 . The equipment of claim 30 , wherein the means to provide a flow of gas is configured to provide the flow of gas in a direction that is essentially parallel to the substrate surfaces.
34 . The equipment of claim 30 , wherein the means to provide a flow of gas further comprises means for heating the gas wherein the heating means is capable of heating the gas to at least 100° C.