Magnetically enhanced plasma oxide etch using hexafluorobutadiene

A method for etching an oxide layer, comprising the steps of:

• providing a plasma etch reactor including a vacuum chamber, a pedestal electrode disposed inside said chamber and having a support surface for supporting thereon a substrate having said oxide layer to be etched, and at least one magnetic coil positioned adjacent said chamber;
• flowing into said chamber an etching gas mixture comprising hexafluorobutandiene;
• applying inside said chamber a magnetic field having a component parallel to said support surface by powering said at least one magnetic coil;
• and
• applying RF electrical power to said pedestal electrode and exciting said etching gas mixture into a plasma to thereby etch a hole into said oxide layer defined by a patterned mask overlying said oxide layer;
• wherein in a first step said magnetic field is applied to a first field strength and wherein in a second step said magnetic field is applied to a second field strength less than said first field strength.

A method for etching an oxide layer, comprising the steps of:

• providing a plasma etch reactor chamber including a vacuum chamber and a pedestal electrode disposed inside said chamber for supporting on a support surface thereof a substrate having said oxide layer to be etched;
• flowing into said chamber an etching gas mixture comprising (a) a fluorocarbon having at least four carbon atoms and an F/C ratio of less than 2, (b) oxygen, and (c) a chemically inactive carrier gas selected from the group consisting of argon and xenon;
• applying inside said chamber a magnetic field having components parallel to said support surface of said pedestal electrode;
• and
• applying RF electrical power to said pedestal electrode and exciting said etching gas mixture into a plasma to thereby etch a hole into said oxide layer defined by a patterned mask overlying said oxide layer;
• vacuum pumping said chamber to maintain a residence time of said etching gas mixture in said chamber of no more than 70 milliseconds.

A method of etching a hole in an oxide layer, comprising the steps of:

• providing a reactive ion plasma etch reactor including a vacuum chamber;
• flowing into said chamber an etching gas mixture comprising a first amount of C4F6, a second amount of O2, and a third amount of Ar and containing essentially no carbon monoxide;
• applying a magnetic field in said chamber including a component parallel to said oxide layer;
• applying RF power to a pedestal electrode supporting a substrate containing said oxide layer and exciting said etching gas mixture into a plasma to etch said oxide layer.

In a plasma etch reactor including a vacuum chamber and a pedestal electrode including a support surface disposed in said chamber, a method for etching an oxide layer in a substrate supported on support surface of said pedestal electrode, comprising two sequentially performed steps each comprising the sub-steps of:

• flowing into said chamber an etching gas mixture comprising (a) a fluorocarbon and (b) a chemically inactive carrier gas selected from the group consisting of argon and xenon;
• applying a magnetic field adjacent to said pedestal electrode;
• and
• applying RF electrical power to said pedestal electrode and exciting said etching gas mixture into a plasma to thereby etch a hole into said oxide layer defined by a patterned mask overlying said oxide layer;
• wherein during a first one of said steps said magnetic field has a first field strength level and during said a subsequent second one of said steps said magnetic field has a second field strength level less than said first field strength level.

In a plasma etch reactor including a vacuum chamber, a pedestal with a support surface disposed within said chamber, a method for etching an oxide layer in a substrate supported on said support surface, comprising two sequentially performed steps each comprising the sub-steps of:

• flowing into said chamber an etching gas mixture comprising (a) a fluorocarbon having at least four carbon atoms and an F/C ratio of less than 2, (b) oxygen, and (c) a chemically inactive carrier gas selected from the group consisting of argon and xenon;
• applying inside said chamber a magnetic field having a component parallel to said support surface;
• and
• applying RF electrical power to said pedestal electrode and exciting said etching gas mixture into a plasma to thereby etch a hole into said oxide layer defined by a patterned mask overlying said oxide layer;
• wherein a ratio of a flow of said oxygen to a flow of said fluorocarbon is higher in a first one of said steps than in a subsequent second one of said steps.

A method for etching an oxide layer, comprising the steps of:

• providing a plasma etch reactor chamber having a pedestal electrode including a support surface for supporting a substrate having said oxide layer to be etched;
• flowing into said chamber an etching gas mixture comprising (a) a fluorocarbon selected from the group consisting of C4F6 and C5F8, (b) O2, and (c) a chemically inactive carrier gas selected from the group consisting of Ar and Xe, said etching gas mixture including essentially no CO;
• applying a magnetic field having a component parallel to said support surface;
• and
• applying RF electrical power to said pedestal electrode and exciting said etching gas mixture into a plasma to thereby etch a hole into said oxide layer defined by a patterned mask overlying said oxide layer.