Method of dry etching in semiconductor device processing

A method of producing a semiconductor device employing an etch-back planarization step comprising the steps of:

• applying a first oxide layer over a patterned metal layer;
• applying a second SOG layer over said first layer;
• utilizing an etching gas mixture comprising a carbon fluoride gas, C.sub.n F.sub.2n+2, wherein n is an integer, and an inert gas;
• creating a plasma wherein fluorine radicals, F*, are liberated in the plasma;
• providing an absorption layer comprising inert gas molecules on an etching surface of said first and second layers;
• and
• applying the fluorine radicals, F*, to the etching surface of said first and second layers to a predetermined depth to form a more planarized surface;
• wherein the formed absorption layer on the etching surface provides a buffering effect on the application of the fluorine radicals, F*, to the etching surface thereby permitting enhancement of the etching rate while maintaining controlled etching uniformity.

A method of producing a semiconductor device including the planarization of an exposed surface of the semiconductor wafer during the practice of the method comprising the steps of:

• providing reactive ion etching system employing a gas medium comprising a mixture of a carbon fluoride gas, C.sub.n F.sub.2n+2, wherein n is an integer, and an inert gas, said gas mixture comprising a gas mixture ratio of carbon fluoride gas/inert gas in the range between about 2%/98% to 95%/5%;
• placing the semiconductor wafer in a plasma generated by the system including a high volume of fluorine radicals, F*;
• providing an absorption layer comprising inert gas molecules on a surface of the semiconductor wafer;
• and
• etching the surface of the semiconductor wafer with the application of the fluorine radicals, F*, to the surface;
• wherein the formed absorption layer on the etching surface provides a buffering effect on the application of the fluorine radicals, F*, to the etching surface thereby permitting enhancement of the etching rate while maintaining controlled etching uniformity.

A method of producing a semiconductor device including the planarization of an exposed surface of a semiconductor wafer during the practice of the method comprising the steps of:

• providing a reactive ion etching system having an anode electrode and a cathode electrode in spatial, parallel relation and having a predetermined gap width therebetween;
• employing a gas medium comprising a mixture of a carbon fluoride gas, C.sub.n F.sub.2n+2, wherein n is an integer, and an inert gas, said gas mixture comprising a gas mixture ratio of carbon fluoride gas/inert gas in the range from about 2%-20% to about 70%-95% with a corresponding gap width in the range from about 15 mm to about 50 mm;
• placing the semiconductor wafer between said electrodes and in a plasma generated by the system producing a high volume of fluorine radicals, F*;
• and
• etching the exposed surface of the semiconductor wafer with the application of the fluorine radicals, F*, to the surface;
• wherein the volume of inert gas in the carbon fluoride gas, C.sub.n F.sub.2n+2, for a given electrode gap width creates a buffering effect on the application of the fluorine radicals, F*, to the etching surface enhancing the etching rate while maintaining etching uniformity.

A method of producing a semiconductor device including the planarization of an exposed surface of a semiconductor wafer during the practice of the method comprising the steps of:

• sequentially depositing first and second oxide layers on a support surface of the wafer, said oxide layers of different oxide type wherein said second layer has a selectivity greater than one and said first layer has a selectivity less than 1;
• providing reactive ion etching system using an etching medium comprising a carbon fluoride gas, C.sub.n F.sub.2n+2, wherein n is an integer;
• and
• etching said second oxide layer with an etching medium having a selectivity greater than one so as to etch said second oxide layer at a rate faster than said first oxide layer until exposure of a substantial portion of said first oxide layer;
• and
• etching said first oxide layer with an etching medium having a selectivity less than one so as to etch said first oxide layer at a rate faster than said second oxide layer until the surfaces of the first and second oxide layers are substantially co-planar.

A method of producing a semiconductor device including the planarization of an exposed surface of a semiconductor wafer during the practice of the method comprising the steps of:

• providing a reactive ion etching system employing a gas medium comprising a carbon fluoride gas, C.sub.n F.sub.2n+2, wherein n is an integer, and an inert gas and wherein the applied RF power is in the range of 400 W to 800 W, the gas flow rate is in the range of 1:100 to 30:1, the total gas flow is in the range of 100 sccm to 200 sccm and the system pressure is in the range of 200 mTorr to 300 mTorr producing a plasma having a high volume of fluorine radicals, F*;
• placing the semiconductor wafer in a plasma generated by the reactive ion etching system including a high volume of fluorine radicals, F*;
• providing an absorption layer comprising inert gas molecules on a surface of the semiconductor wafer;
• and
• etching the surface of the semiconductor wafer by the application of the fluorine radicals, F*, to the surface;
• wherein the formed absorption layer on the etching surface provides a buffering effect on the application of the fluorine radicals, F*, to the etching surface thereby permitting enhancement of the etching rate while maintaining controlled etching uniformity.