Platinum group impurity recovery liquid and method for recovering platinum group impurity
AssigneeNEC Corporation
InventorKaori Watanabe
Life of this patent
Estimating the term…
Abstract
A mixed aqueous solution containing HCl with a concentration of 10 to 25% by weight, H2O2 with a concentration of 2 to 5% by weight, and HF with a concentration of 0.01 to 2% by weight or a mixed aqueous solution containing H2SO4 with a concentration of 65 to 82% by weight, H2O2 with a concentration of 4 to 16% by weight, and HF with a concentration of 0.01 to 2% by weight is used as a platinum group impurity recovery liquid. The recovery liquid is dripped onto a silicon substrate surface or a film thereon so as to scan the entire surface of the substrate with the droplets. As a result, the platinum group impurity is dissolved into the recovery liquid, and the platinum group impurity is thus recovered.
Claims20
A platinum group impurity recovery liquid for recovering a platinum group impurity on a silicon substrate surface or in a film thereon, the recovery liquid being a mixed aqueous solution containing HCl with a concentration of 10 to 25% by weight, H2O2 with a concentration of 2 to 5% by weight, and HF with a concentration of 0.01 to 2% by weight.
A platinum group impurity recovery liquid for recovering a platinum group impurity on a silicon substrate surface or in a film thereon, the recovery liquid being a mixed aqueous solution containing H2SO4 with a concentration of 65 to 82% by weight, H2O2 with a concentration of 4 to 16% by weight, and HF with a concentration of 0.01 to 2% by weight.
A method for recovering a platinum group impurity for recovering a platinum group impurity on a silicon substrate surface or in a film thereon, comprising the steps of:
- making a droplet of the platinum group impurity recovery liquid being a mixed aqueous solution containing HCl with a concentration of 10 to 25% by weight, H2O2 with a concentration of 2 to 5% by weight, and HF with a concentration of 0.01 to 2% by weight contact a silicon substrate surface or a film thereon so as to scan the silicon substrate surface with the droplet of the recovery liquid;
- dissolving the platinum group impurity into the droplet;
- and
- recovering the platinum group impurity.
A method for recovering a platinum group impurity for recovering a platinum group impurity on a silicon substrate surface or in a film thereon, comprising the steps of:
- making a droplet of the platinum group impurity recovery liquid being a mixed aqueous solution containing H2SO4 with a concentration of 65 to 82% by weight, H2O2 with a concentration of 4 to 16% by weight, and HF with a concentration of 0.01 to 2% by weight contact a silicon substrate surface or a film thereon so as to scan the silicon substrate surface with the droplets of the recovery liquid;
- dissolving the platinum group impurity into the droplet;
- and
- recovering the platinum group impurity.
A method for recovering a platinum group impurity for recovering a platinum group impurity on a silicon substrate surface or in a film thereon, comprising the steps of:
- dripping a droplet of the platinum group impurity recovery liquid being a mixed aqueous solution containing HCl with a concentration of 10 to 25% by weight, H2O2 with a concentration of 2 to 5% by weight, and HF with a concentration of 0.01 to 2% by weight onto a silicon substrate surface or a film thereon;
- and
- recovering the recovery liquid after the recovery liquid is left standing for a predetermined period of time, wherein an operation of said dropping and recovering is repeated one or more times.
A method for recovering a platinum group impurity for recovering a platinum group impurity on a silicon substrate surface or in a film thereon, comprising the steps of:
- dripping a droplet of the platinum group impurity recovery liquid being a mixed aqueous solution containing H2SO4 with a concentration of 65 to 82% by weight, H2O2 with a concentration of 4 to 16% by weight, and HF with a concentration of 0.01 to 2% by weight onto a silicon substrate surface or a film thereon;
- and
- recovering the recovery liquid after the recovery liquid is left standing for a predetermined period of time, wherein an operation of said dripping and recovering is repeated one or more times.
Dependencies are inferred from the claim text.