Method for pretreating and recovering a rare gas from a gas contaminant stream exiting an etch chamber

A method for pretreating and recovering xenon from a nitrogen-based exhaust stream exiting an etch chamber, comprising the steps of:

• receiving a xenon-containing, nitrogen-based exhaust stream from an etch chamber, said xenon-containing, nitrogen-based exhaust stream having a composition of gas species comprising the xenon, gaseous impurities and nitrogen, said xenon in an amount greater than 0 mol % and up to about 0.5 mol %, and said gaseous impurities comprising hydrofluorocarbons, perfluorocarbons, carbon monoxide (CO), hydrogen fluoride, silicon fluorides and carbon tetrafluoride;
• wherein each of said gaseous impurities of said hydrofluorocarbons, perfluorocarbons, carbon monoxide, silicon fluorides and carbon tetrafluoride is in an amount greater than 0 mol % and up to about 1 mol %, and further wherein said hydrogen fluoride is in an amount greater than 0 mol % and up to about 2 mol %;
• pretreating the xenon-containing, nitrogen-based exhaust stream by introducing the same into a pretreatment system, said pretreatment system comprising a burner, a scrubber and an adsorber to (x) combust a substantial portion of the hydrofluorocarbons and the perfluorocarbons and the carbon monoxide into combustion products comprising carbon dioxide and water vapor to create a diluted, xenon-containing, nitrogen-based exhaust stream, (y) remove substantially all of the hydrogen fluoride and the silicon fluorides in the scrubber, and (z) adsorb substantially all of the carbon dioxide and the water vapor onto an adsorbent of the adsorber to create a pre-treated, diluted xenon-containing, nitrogen-based exhaust stream;
• withdrawing the pretreated, diluted, xenon-containing, nitrogen-based exhaust stream from an outlet of the adsorber, said pretreated, diluted, xenon-containing, nitrogen-based exhaust stream having a composition comprising said xenon, said gaseous impurities and said nitrogen, wherein said xenon is in an amount greater than 0 mol % and less than about 0.05 mol %, and said gaseous impurities remaining after the pretreatment comprises oxygen in an amount greater than 0.01 mol % and up to about 2 mol %, carbon tetrafluoride in an amount greater than 0 mol % and up to about 0.01 mol %, carbon dioxide in an amount ranging from 0.00001 mol % up to about 0.0005 mol %;
• cooling the pretreated, diluted xenon-containing, nitrogen-based exhaust stream to a first non-cryogenic temperature;
• followed by
• introducing the pretreated, diluted, xenon-containing, nitrogen-based exhaust stream into a temperature swing adsorber (TSA) containing an adsorbent bed therein, wherein said adsorbent bed contains an AgX adsorbent;
• and
• adsorbing the xenon onto the AgX adsorbent preferentially over the gaseous impurities in the pretreated, diluted, xenon-containing, nitrogen-based exhaust stream that are remaining after the step of pretreating.

A method for pretreating and recovering a rare gas from a nitrogen-based exhaust stream exiting an etch chamber and recovering the rare gas from the nitrogen-based exhaust stream exiting the etch chamber, comprising the steps of:

• receiving a rare-gas-containing, nitrogen-based exhaust stream from an etch chamber, said rare-gas-containing, nitrogen-based exhaust stream having a composition of gas species comprising the rare gas, gaseous impurities and nitrogen, said rare gas in an amount greater than 0 mol % and up to about 0.5 mol %, said gaseous impurities comprising (i) hydrofluorocarbons represented by the general formula CxHyFz, where each of x, y and z can have any integers that range from 1 to 5, with the proviso that when x=1, y+z=4, and when x=2 to 5, y+z−2x=−2, 0 or 2, (ii) perfluorocarbons represented by the general formula CxFy where x can have any integer values from 2 to 5, where y−2x=−2, 0, or 2, (iii) carbon monoxide (CO), (iv) hydrogen fluoride (HF), (v) silicon fluoride (SiF4) and (vi) carbon tetrafluoride (CF4), wherein each of said gaseous impurities of said CxHyFz, CxFy, CO, SiF4 and CF4 is in an amount greater than 0 mol % and up to about 1 mol %, and HF is in an amount greater than 0 mol % and up to about 2 mol %;
• pretreating the rare-gas-containing, nitrogen-based exhaust stream by introducing the rare-gas-containing, nitrogen-based exhaust stream into a pretreatment system, said pretreatment system comprising a burner, a scrubber and an adsorber to (x) combust a substantial portion of the CxHyFz and the CxFy into combustion products comprising carbon dioxide (CO2) and water vapor (H2O) to create a diluted, rare-gas-containing, nitrogen-based exhaust stream, (y) remove substantially all of the HF and the SiF4 in the scrubber, and (z) adsorb substantially all of the CO2 and the H2O onto an adsorbent of the adsorber to create a pretreated, diluted, rare-gas-containing, nitrogen-based exhaust stream;
• withdrawing the pretreated, diluted, rare-gas-containing, nitrogen-based exhaust stream from an outlet of the adsorber, said pretreated, diluted, rare-gas containing, nitrogen-based exhaust stream having a composition comprising the rare gas, the gaseous impurities and the nitrogen, said rare gas in an amount greater than 0 mol % and less than about 0.05 mol % xenon, and said gaseous impurities remaining after the pretreatment comprising oxygen (O2) in an amount greater than 0.01 mol % and up to about 2 mol %, CF4 in an amount greater than 0 mol % and up to about 0.01 mol % and CO2 in an amount ranging from 0.00001 mol % up to about 0.0005 mol %;
• cooling the pretreated, diluted, rare-gas-containing, nitrogen-based exhaust stream to a first noncryogenic temperature;
• followed by
• introducing the pretreated, diluted, rare-gas-containing, nitrogen-based exhaust stream into a rare gas recovery unit;
• and
• recovering the rare gas from the diluted, rare-gas-containing, nitrogen-based exhaust stream.

A pretreatment system for pretreating a rare-gas-containing, nitrogen-based exhaust stream exiting an etch chamber, prior to recovery of the rare gas from the rare-gas-containing, nitrogen-based exhaust stream, said pretreatment system comprising:

• a collection manifold having an inlet operably connected to upstream etch chambers and an outlet operably connected to a pretreatment system, said collection manifold configured to receive a signal from each of the upstream etch chambers, said signal indicative of the presence or non-presence of the rare gas in an exhaust stream generated from one of the corresponding upstream etch chambers, said collection manifold in response to said signal configured to receive the rare-gas containing, nitrogen-based exhaust stream, and said collection manifold in response to said signal configured to exclude receiving a non-rare-gas, nitrogen-based exhaust stream devoid of the rare gas;
• and
• the pretreatment system comprising a burner, a scrubber and a adsorber, said pretreatment system configured to (i) combust a substantial portion of carbon monoxide, hydrofluorocarbon and perfluorocarbon impurities into carbon dioxide and water vapor, (ii) remove a substantial portion of hydrogen fluoride and silicon tetrafluoride impurities in the scrubber, and (iii) adsorb substantially all of the carbon dioxide and the water vapor onto an adsorbent of the adsorber so as to create a pretreated, diluted, rare-gas containing, nitrogen-based exhaust stream.

A system for pretreating and recovering xenon from a xenon-containing, nitrogen-based exhaust stream exiting an etch chamber, comprising:

• a collection manifold having an inlet operably connected to upstream etch chambers and an outlet operably connected to a pretreatment system, said collection manifold configured to receive a signal from each of the upstream etch chambers, said signal indicative of the presence or non-presence of xenon in an exhaust stream generated from one of the corresponding upstream etch chambers, said collection manifold in response to said signal configured to receive a xenon-containing, nitrogen-based exhaust stream, and said collection manifold in response to said signal configured to exclude receiving a non-xenon-containing, nitrogen-based exhaust stream;
• the pretreatment system comprising a burner, a scrubber and a adsorber, said pretreatment system configured to (i) combust a substantial portion of first impurities comprising carbon monoxide, hydrofluorocarbon and perfluorocarbon into carbon dioxide and water vapor, (ii) remove a substantial portion of second impurities comprising hydrogen fluoride and silicon tetrafluoride in the scrubber, and (iii) adsorb a substantial portion of third impurities comprising the carbon dioxide and the water vapor onto an adsorbent of the adsorber to create a pretreated, diluted xenon-containing, nitrogen-based exhaust stream;
• and
• a temperature swing adsorber (TSA) containing an adsorbent bed therein, wherein said adsorbent bed contains an AgX adsorbent, said TSA having an inlet that is operably connected to an outlet of the adsorber, said TSA configured to receive the pretreated, diluted, xenon-containing, nitrogen-based exhaust stream from the outlet of the adsorber for preferential recovery over the first, the second and third impurities of substantially all of the xenon in the xenon-containing, nitrogen-based exhaust stream.

A system for pretreating and recovering a rare gas from a rare-gas-containing, nitrogen-based exhaust stream exiting an etch chamber, comprising:

• a collection manifold having an inlet operably connected to upstream etch chambers and said collection manifold having an outlet that is operably connected to a pretreatment system, said collection manifold configured to receive a signal from each of the upstream etch chambers, said signal indicative of the presence or non-presence of the rare gas in an exhaust stream generated from one of the corresponding upstream etch chambers, said collection manifold in response to said signal configured to receive a rare-gas-containing, nitrogen-based exhaust stream, and said collection manifold in response to said signal is configured to exclude receiving a non-rare-gas-containing, nitrogen-based exhaust stream;
• the pretreatment system comprising a burner, a scrubber and a adsorber, said pretreatment system configured to (i) combust a substantial portion of first impurities comprising carbon monoxide, hydrofluorocarbon and perfluorocarbon impurities into carbon dioxide and water vapor, (ii) remove a substantial portion of second impurities comprising hydrogen fluoride and silicon tetrafluoride in the scrubber, and (iii) adsorb a substantial portion of third impurities of the carbon dioxide and the water vapor onto an adsorbent of the adsorber to create a pretreated, diluted, rare-gas-containing, nitrogen-based exhaust stream;
• and
• a rare gas recovery unit configured to receive the pretreated, diluted, rare gas, nitrogen-based exhaust stream from the outlet of the adsorber for preferential recovery over the first, the second and the third impurities of substantially all of the rare gas from the rare-gas-containing, nitrogen-based exhaust stream.

A method for pretreating a rare-gas-containing, nitrogen-based exhaust stream exiting an etch chamber, prior to recovery of the rare gas from the rare-gas-containing, nitrogen-based exhaust stream, said method comprising the steps of:

• receiving the rare-gas-containing, nitrogen-based exhaust stream from the etch chamber, said rare-gas-containing, nitrogen-based exhaust stream having a composition of gas species comprising (a) said rare gas, (b) gaseous impurities and (c) nitrogen (N2), said rare gas in an amount greater than 0 mol % and up to about 0.5 mol %, said gaseous impurities comprising (i) hydrofluorocarbons (ii) perfluorocarbons (iii) carbon monoxide (CO);
• (iv) hydrogen fluoride (HF);
• (v) silicon fluoride (SiF4);
• and (vi) carbon tetrafluoride (CF4), wherein each of said gaseous impurities of said hydrofluorocarbons, perfluorocarbons, CO, SiF4 and CF4 is in an amount greater than 0 mol % and up to about 1 mol %, and further wherein HF is in an amount greater than 0 mol % and up to about 2 mol %;
• pretreating the rare-gas-containing, nitrogen-based exhaust stream by introducing the rare-gas-containing, nitrogen-based exhaust stream into a pretreatment system, said pretreatment system comprising a burner, a scrubber and an adsorber, said pretreating comprising (x) combusting a substantial portion of the CO, the hydrofluorocarbons, the perfluorocarbons into combustion products comprising carbon dioxide (CO2) and water vapor (H2O) to create a diluted, rare-gas-containing, nitrogen-based exhaust stream;
• (y) removing substantially all of the HF and the SiF4 in the scrubber;
• and (z) adsorbing substantially all of the CO2 and the H2O onto an adsorbent to create a pretreated, diluted, rare-gas-containing, nitrogen-based exhaust stream;
• and
• withdrawing the pretreated, diluted, rare-gas-containing, nitrogen-based exhaust stream from an outlet of the adsorber of the pretreatment system, said pretreated, diluted, rare-gas-containing, nitrogen-based exhaust stream having a composition comprising the rare gas, the gaseous impurities and the N2, said rare gas in an amount greater than 0 mol % and less than about 0.05 mol %, and said gaseous impurities remaining after the step of pretreating comprising oxygen (O2) in an amount greater than 0.01 mol % and up to about 2 mol %, CF4 in an amount greater than 0 mol % and up to about 0.01 mol %, CO2 in an amount ranging from 0.00001 mol % and up to about 0.0005 mol %.

A method of pretreating a rare-gas containing, nitrogen-based exhaust stream from an etch chamber, comprising:

• introducing a rare-gas-containing, nitrogen-based exhaust stream from the etch chamber into a pretreatment system;
• and
• pretreating the rare-gas-containing, nitrogen-based exhaust stream by (x) combusting a substantial portion of combustible gaseous impurities into combustion products comprising carbon dioxide (CO2) and water vapor (H2O) to create a diluted, rare-gas-containing, nitrogen-based exhaust stream;
• (y) removing a substantial portion of corrosive fluorides;
• and (z) adsorbing substantially all of the CO2 and the H2O onto an adsorbent of to create a pretreated, diluted, rare-gas-containing, nitrogen-based exhaust stream.