Method for stripping a photo resist on an aluminum alloy
AssigneeFujitsu Limited
InventorMoritaka Nakamura
Life of this patent
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Abstract
An interconnection pattern made of an aluminum alloy, such as Al—Cu, on a semiconductor IC, is dry etched in an etching gas containing a chlorine component. A photo resist stripping process is carried out at a location down stream of the etching process using a conventional stripping gas, such as CF4+02, at room temperature. Before the resist-stripped substrate is exposed to open air, the substrate is heated in a vacuum to a temperature above 100° C., to remove residual chlorine components.
Claims36
A method for forming an aluminum-copper alloy wiring pattern on an insulation layer which is formed on a semiconductor substrate, an entire surface of which substrate is immune to damage from plasma due to the insulation layer, comprising the steps of:
- forming, on the semiconductor substrate, over the insulation layer, a layer of aluminum alloy containing copper;
- forming a resist pattern on said aluminum alloy layer to create a resist layer portion and an exposed layer portion;
- etching the exposed layer portion using the resist pattern as a mask by using accelerated reactive ions in gas plasma containing at least chlorine ions to form a patterned layer,
- wherein a residual chlorine component is sputtered by ion bombardment on the resist pattern and on the insulation layer covering the semiconductor substrate;
- subsequent to etching the exposed layer portion,
- downstream ashing the resist pattern isotropically by exposing the resist pattern to an atmosphere containing only non-ionic species, said atmosphere being created by generating gas plasma from reaction gas containing oxygen by applying electromagnetic power and directing non-ionic species in said gas plasma;
- and
- after the downstream ashing step, removing the residual chlorine component from the patterned layer and the insulation layer by heating the substrate with the patterned layer thereon in vacuum between 100° C. and 300° C. by a heated stage whereon the substrate is placed.
A method for forming an aluminum-copper alloy wiring pattern on an insulation layer which is formed on a semiconductor substrate, an entire surface of which substrate is immune to damage from plasma due to the insulation layer, comprising the steps of:
- forming, on the semiconductor substrate, over the insulation layer, a layer of aluminum alloy containing copper;
- forming a resist pattern on said aluminum alloy layer to create a resist layer portion and an exposed layer portion;
- etching the exposed layer portion using the resist pattern as a mask by reactive ion etching using gas plasma containing chlorine ions in a first reaction chamber to form a patterned layer,
- wherein a residual chlorine component is sputtered by ion bombardment on the resist pattern and on the insulation layer covering the semiconductor substrate;
- transferring the substrate to a second reaction chamber without exposing the substrate to an external atmosphere;
- and
- downstream ashing the resist pattern isotropically by exposing the resist pattern to an atmosphere containing only non-ionic species in the second reaction chamber, said atmosphere being created by generating gas plasma from reaction gas containing oxygen by applying electromagnetic power and directing non-ionic species in said gas plasma into the second reaction chamber;
- wherein the substrate with the patterned layer thereon is maintained between 100° C. and 200° C., by a heated stage whereon the substrate is placed, during the downstream ashing step to remove the residual chlorine component from the patterned layer and the insulation layer.
A method for forming an aluminum-copper alloy wiring pattern on an insulation layer which is formed on a semiconductor substrate, an entire surface of which substrate is immune to damage from plasma due to the insulation layer, comprising the steps of:
- forming, on the semiconductor substrate, over the insulation layer, a layer chosen to have a thickness of 1-4 μm from an aluminum alloy containing 2-4% copper;
- forming a resist pattern on said aluminum alloy layer to create a resist layer portion and an exposed layer portion;
- etching the exposed layer portion using the resist pattern as a mask by reactive etching using gas plasma containing chlorine ions to form a patterned layer,
- wherein a residual chlorine component is sputtered by ion bombardment on the resist pattern and on the insulation layer covering the semiconductor substrate, said residual chlorine component including at least one of cuprous chloride, cupric chloride and a mixture of Cu, Cl, Al and C;
- downstream ashing the resist pattern isotropically by exposing the resist pattern to gas plasma containing only non-ionic species from reaction gas containing oxygen to which electromagnetic power has been applied, and from the ionic species of the gas plasma;
- and
- removing the residual chlorine component from the patterned layer and the insulation layer by heating the substrate with the patterned layer thereon in vacuum between 250° C. and 300° C. by a heated stage whereon the substrate is placed.
A method for forming a metal wiring pattern underlayered by an insulation layer disposed on a semiconductor substrate, comprising the steps of:
- forming, on the semiconductor substrate having the insulation layer thereon, a metal layer containing copper;
- forming a resist pattern on said metal layer to create a resist layer portion and an exposed layer portion;
- etching the exposed layer portion using the resist pattern as a mask by using accelerating reactive ions in gas plasma containing at least chlorine ions to form a patterned layer,
- subsequent to etching the exposed layer pattern,
- downstream ashing the resist pattern isotropically by exposing the resist pattern to an atmosphere containing only non-ionic species, said atmosphere being created by generating gas plasma from reaction gas containing oxygen by applying electromagnetic power and directing only the non-ionic species to the substrate;
- and
- removing the residual chlorine component from the patterned layer and the insulation layer by heating the substrate with the patterned layer thereon, by a heated stage whereon the substrate is placed, such that the surface density of residual chlorine atoms falls below the order of two-digit figures in cps.
A method for forming, in a single wafer reactor, an aluminum-copper alloy wiring pattern on an insulation layer which is formed on a semiconductor substrate, an entire surface of which substrate is immune to damage from plasma due to the insulation layer, comprising the steps of:
- forming, on the semiconductor substrate, over the insulation layer, a layer of aluminum alloy containing copper;
- forming a resist pattern on said aluminum alloy layer to create a resist layer portion and an exposed layer portion;
- etching the exposed layer portion using the resist pattern as a mask by using accelerated reactive ions in gas plasma containing at least chlorine ions to form a patterned layer,
- wherein a residual chlorine component is sputtered by ion bombardment on the resist pattern and on the insulation layer covering the semiconductor substrate;
- subsequent to etching the exposed layer portion,
- downstream ashing the resist pattern isotropically by exposing the resist pattern to an atmosphere containing only non-ionic species, said atmosphere being created by generating gas plasma from reaction gas containing oxygen by applying electromagnetic power and directing non-ionic species in said gas plasma;
- and
- after the downstream ashing step, removing the residual chlorine component from the patterned layer and the insulation layer by heating the substrate with the patterned layer thereon in vacuum between 100° C. and 300° C. by a heated stage whereon the substrate is placed.
A method for forming, in a single wafer reactor, an aluminum-copper alloy wiring pattern on an insulation layer which is formed on a semiconductor substrate, an entire surface of which substrate is immune to damage from plasma due to the insulation layer, comprising the steps of:
- forming, on the semiconductor substrate, over the insulation layer, a layer of aluminum alloy containing copper;
- forming a resist pattern on said aluminum alloy layer to create a resist layer portion and an exposed layer portion;
- etching the exposed layer portion using the resist pattern as a mask by reactive ion etching using gas plasma containing chlorine ions in a first reaction chamber to form a patterned layer,
- wherein a residual chlorine component is sputtered by ion bombardment on the resist pattern and on the insulation layer covering the semiconductor substrate;
- transferring the substrate to a second reaction chamber without exposing the substrate to an external atmosphere;
- and
- downstream ashing the resist pattern isotropically by exposing the resist pattern to an atmosphere containing only non-ionic species in the second reaction chamber, said atmosphere being created by generating gas plasma from reaction gas containing oxygen by applying electromagnetic power and directing non-ionic species in said gas plasma into the second reaction chamber;
- wherein the substrate with the patterned layer thereon is maintained between 100° C. and 200° C., by a heated stage whereon the substrate is placed, during the downstream ashing step to remove the residual chlorine component from the patterned layer and the insulation layer.
A method for forming, in a single wafer reactor, an aluminum-copper alloy wiring pattern on an insulation layer which is formed on a semiconductor substrate, an entire surface of which substrate is immune to damage from plasma due to the insulation layer, comprising the steps of:
- forming, on the semiconductor substrate, over the insulation layer, a layer chosen to have a thickness of 1-4 μm from an aluminum alloy containing 2-4% copper;
- forming a resist pattern on said aluminum alloy layer to create a resist layer portion and an exposed layer portion;
- etching the exposed layer portion using the resist pattern as a mask by reactive etching using gas plasma containing chlorine ions to form a patterned layer,
- wherein a residual chlorine component is sputtered by ion bombardment on the resist pattern and on the insulation layer covering the semiconductor substrate, said residual chlorine component including at least one of cuprous chloride, cupric chloride and a mixture of Cu, Cl, Al and C;
- downstream ashing the resist pattern isotropically by exposing the resist pattern to gas plasma containing only non-ionic species from reaction gas containing oxygen to which electromagnetic power has been applied, and from the ionic species of the gas plasma;
- and
- removing the residual chlorine component from the patterned layer and the insulation layer by heating the substrate with the patterned layer thereon in vacuum between 250° C. and 300° C. by a heated stage whereon the substrate is placed.
A method for forming, in a single wafer reactor, a metal wiring pattern underlayered by an insulation layer disposed on a semiconductor substrate, comprising the steps of:
- forming, on the semiconductor substrate having the insulation layer thereon, a metal layer containing copper;
- forming a resist pattern on said metal layer to create a resist layer portion and an exposed layer portion;
- etching the exposed layer portion using the resist pattern as a mask by using accelerating reactive ions in gas plasma containing at least chlorine ions to form a patterned layer,
- subsequent to etching the exposed layer pattern,
- downstream ashing the resist pattern isotropically by exposing the resist pattern to an atmosphere containing only non-ionic species, said atmosphere being created by generating gas plasma from reaction gas containing oxygen by applying electromagnetic power and directing only the non-ionic species to the substrate;
- and
- removing the residual chlorine component from the patterned layer and the insulation layer by heating the substrate with the patterned layer thereon, by a heated stage whereon the substrate is placed, such that the surface density of residual chlorine atoms falls below the order of two-digit figures in cps.
Dependencies are inferred from the claim text.