Surface treatment of indium phosphide utilizing chemical roughening of the surface
AssigneeHughes Aircraft Company
InventorCatherine Ngo
Life of this patent
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Abstract
A surface (30) of a wafer of indium phosphide (22) is treated by first etching the surface (30) with an aqueous solution of nitric acid and ceric ammonium nitrate. A toughening solution of about 4 parts by volume of acetic acid, about 4 parts by volume nitric acid, and about 1 part by volume hydrobromic acid is prepared and mixed. The roughening solution is contacted to the etched surface (30) of the wafer of indium phosphide (22) for about 15 to about 30 seconds to roughen the surface of the indium phosphide. Reaction products may be removed from the surface in aqueous hydrofluoric solution, and metal may be deposited upon the toughened surface in a strongly adhering layer (28).
Claims16
A process for preparing the surface of a piece of lndlum phosphide, comprising the steps of:
- supplying a piece of indium phosphide;
- etching a surface of the piece of indium phosphide with an aqueous solution of nitric acid and ceric ammonium nitrate;
- preparing and mixing a roughening solution of acetic acid, nitric acid, and hydrobromic acid;
- and
- contacting the roughening solution to the etched surface of the piece of indium phosphide for a contact time sufficient to roughen the surface of the indium phosphide.
A process for preparing the surface of a piece of indium phosphide, comprising the steps of:
- supplying a piece of indium phosphide;
- etching a surface of the piece of indium phosphide with an aqueous solution of nitric acid and ceric ammonium nitrate;
- preparing and mixing a toughening solution of about 4 parts by volume of acetic acid, about 4 parts by volume nitric acid, and about 1 part by volume hydrobromic acid;
- and
- contacting the toughening solution to the etched surface of the piece of indium phosphide for from about 15 to about 30 seconds to roughen the surface of the indium phosphide.
A process for preparing the surface of a piece of indium phosphide, comprising the steps of:
- supplying a wafer of indium phosphide having microelectronic circuitry deposited on a front side surface thereof and vias formed therethrough;
- masking the vias of the wafer and protecting the front side and microelectronic circuitry from attack;
- etching a back side surface of the piece of indium phosphide with an aqueous solution of nitric acid and ceric ammonium nitrate;
- preparing and mixing a toughening solution of about 4 parts by volume of acetic acid, about 4 parts by volume nitric acid, and about 1 part by volume hydrobromic acid;
- contacting the toughening solution to the etched back side surface of the piece of indium phosphide for from about 15 to about 30 seconds to roughen the back side surface of the wafer;
- contacting aqueous hydrofluoric acid solution to the back side surface of the wafer to remove reaction products from the back side surface;
- removing the mask;
- and
- depositing metal on the back side surface of the wafer.
Dependencies are inferred from the claim text.