Advanced Micro Devices Corporation

Diana M Schonauer

Steven C Avanzino

Kai Yang

Christy Mei-Chu Woo

Darrell M Erb

Kashmir S Sahota

Minh Van Ngo

Bhanwar Singh

Fei Wang

Paul Raymond Besser

Sergey D Lopatin

Subhash Gupta

Amit P Marathe

Pin-Chin Connie Wang

Darin A Chan

Peter A Burke

Subramanian N Venkatkrishnan

Johannes Groschopf

Isidore Salugsugan

Christy Mei-Chu Woo De La Girond'arc

Gerd F C Marxsen

A Ta barrier slurry for Chemical-Mechanical Polishing (CMP) during copper metallization contains an organic additive which suppresses formation of precipitates and copper staining. The organic additive is chosen from a class of compounds which form multiple strong adsorbant bonds to the surface of silica or copper, which provide a high degree of surface coverage onto the reactive species, thereby occupying potential reaction sites, and which are sized to sterically hinder the collisions between two reactant molecules which result in new bond formation. The organic additive-containing slurry cain be utilized throughout the entire polish time. Alternatively, a slurry not containing the organic additive can be utilized for a first portion of the polish, and a slurry containing the organic additive or a polishing solution containing the organic additive can be utilized for a second portion of the polish.

Prevention of precipitation defects on copper interconnects during CMP by use of solutions containing organic compounds with silica adsorption and copper corrosion inhibiting properties

The formation and/or growth of dendrites emanating from Cu or Cu alloy lines into a bordering open dielectric field are prevented or substantially reduced by chemically removing a portion of the surface from the dielectric field and from between the lines after CMP by immersing the wafer in a bath containing a chemical agent. Embodiments include removing up to 60 &angst; of silicon oxide by immersing the wafer in an acidic solution, such as a solution of hydrofluoric acid and water.

Chemically preventing Cu dendrite formation and growth by immersion

For fabricating an interconnect structure within an interconnect opening formed within a porous dielectric material, the interconnect opening is initially formed within a low-K precursor material that is not completely cured. The interconnect opening is then filled with a conductive fill material being contained within the interconnect opening and with a top surface of the conductive fill material within the interconnect opening being exposed. A capping material is formed on the top surface of the conductive fill material, and the capping material is an amorphous alloy or is a microcrystalline alloy having stuffed grain boundaries. A thermal curing process is then performed for curing the low-K precursor material to become a porous low-K dielectric material. The capping material on the top surface of the conductive fill material is impervious to at least one of oxygen, carbon, hydrogen, chlorine, and porogen fragments that are generated as out-gassing volatile by-products from the low-K precursor material during the thermal curing process to preserve the integrity of the interconnect structure. In another aspect for fabricating an interconnect structure, an interconnect opening is formed within a porous dielectric material with opened pores at sidewalls of the interconnect opening. A diffusion barrier material is formed at a bottom wall of the interconnect opening. The diffusion barrier material is then sputtered away from the bottom wall of the interconnect opening and onto the sidewalls of the interconnect opening to substantially fill the opened pores at the sidewalls with the diffusion barrier material. The interconnect opening is then filled with a conductive fill material after the opened pores at the sidewalls of the interconnect opening are filled with the diffusion barrier material.

Interconnect structure formed in porous dielectric material with minimized degradation and electromigration

A Ta barrier slurry for Chemical-Mechanical Polishing (CMP) during copper metallization contains an organic additive which suppresses formation of precipitates and copper staining. The organic additive is chosen from a class of compounds which form multiple strong adsorbant bonds to the surface of silica or copper, which provide a high degree of surface coverage onto the reactive species, thereby occupying potential reaction sites, and which are sized to sterically hinder the collisions between two reactant molecules which result in new bond formation

Ta barrier slurry containing an organic additive

Copper or a low resistivity copper alloy is initially deposited to fill relatively narrow openings leaving relatively wider openings unfilled. A copper alloy having improved electromigration resistance with respect to copper is then selectively deposited to fill the relatively wider openings, thereby improving electromigration resistance without increasing narrow line resistance. Embodiments include annealing after filling the relatively narrow openings and before filling the relatively wider openings, thereby reducing void formation in narrow lines.

Selective copper alloy deposition

The formation and/or growth of dendrites emanating from Cu or Cu alloy lines into a bordering open dielectric field are prevented or substantially reduced by chemically removing a portion of the surface from the dielectric field and from between the lines after CMP by spraying the wafer with a chemical agent. Embodiments include removing up to 60&angst; of silicon oxide by spraying the wafer with an acidic solution, such as a solution comprising acetic acid and ammonium fluoride.

Chemically preventing copper dendrite formation and growth by spraying

The formation and/or growth of dendrites emanating from Cu or Cu alloy lines into a bordering open dielectric field are prevented or substantially reduced by chemically removing a portion of the surface from the dielectric field and between the lines after CMP. Embodiments include removing up to 20 &angst; of silicon oxide by buffing with a solution containing ammonium fluoride, diammonium hydrogen citrate, triammonium citrate and dionized water.

Copper dendrite prevention by chemical removal of dielectric

The formation and/or growth of dendrites emanating from Cu or Cu alloy lines into a bordering open dielectric field are prevented or substantially reduced by chemically removing a portion of the surface from the dielectric field and from between the lines after CMP with a solution comprising HF and H,O. Embodiments include removing up to 50 &angst; of silicon oxide by treating the wafer in a spray acid processor with a solution containing HF and deionized water at a water to acid ratio of about 100:1 to about 250:1.

Prevention of Cu dendrite formation and growth

The formation and/or growth of dendrites emanating from Cu or Cu alloy lines into a bordering open dielectric field are prevented or substantially reduced by chemically removing a portion of the surface from the dielectric field and from between the lines after CMP by double sided scrubbing with a chemical agent. Embodiments include removing portions up to 60 &angst; of silicon oxide by double sided scrubbing with a solution containing ammonium fluoride, diammonium hydrogen citrate, triammonium citrate, and dionized water, with or without a surfactant.

Chemically preventing Cu dendrite formation and growth by double sided scrubbing

The formation and/or growth of dendrites emanating from Cu or Cu alloy lines into a bordering open dielectric field are prevented or substantially reduced by chemically removing a portion of the surface from the dielectric field and from between the lines after CMP by immersion in and/or double sided brush scrubbing with a chemical agent. Embodiments include removing controlled portions up to 50 &angst; of silicon oxide by immersion in and/or double sided brush scrubbing with a solution containing ammonium fluoride, diammonium hydrogen citrate, triammonium citrate, a surfactant and dionized water.

Preventing Cu dendrite formation and growth

Abrasion of Cu metallization during CMP is reduced and residual slurry particulate removal facilitated by employing a CMP slurry containing a dispersion of soft mineral particles having high solubility in dilute acids. Embodiments include CMP Cu metallization with a slurry containing magnesium oxide particles and removing any residual magnesium oxide particles after CMP with an organic acid, such as citric acid or acetic acid, or a dilute inorganic acid, such as hydrochloric, phosphoric, boric or fluoboric acid.

Chemically removable Cu CMP slurry abrasive

The formation and/or growth of dendrites emanating from Cu or Cu alloy lines into a bordering open dielectric field are prevented or substantially reduced by chemically removing a portion of the surface from the dielectric field and from between the lines after CMP with a solution comprising acetic acid and ammonium fluoride. Embodiments include removing up to 60 .ANG., e.g. about 10 .ANG. to about 30 .ANG., of silicon oxide by immersing the wafer in a solution containing at least about 90 wt. % acetic acid and up to about 10 wt. % ammonium fluoride.

Chemical treatment for preventing copper dendrite formation and growth

A multiple-layer interconnect structure in an integrated circuit, is formed using damascene techniques. A first layer interconnect has a first dielectric layer through which at least one first layer conductor extends. A second layer interconnect is then formed on the first layer interconnect. The second layer interconnect also includes a second layer dielectric through which at least one second layer conductor extends. However, the second layer interconnect is created by first forming a thick second later dielectric layer and then reducing the thickness of the second layer dielectric prior to a patterning step. As a result topographical irregularities that may have carried over to the second layer interconnect from the first layer interconnect are removed by providing a substantially planar surface on the second layer dielectric.

Elimination of residual materials in a multiple-layer interconnect

Abrasion of Cu metallization during CMP is reduced and residual slurry particulate removal facilitated by employing a CMP slurry containing a dispersion of iron oxide particles having high solubility in dilute acids. Embodiments include CMP Cu metallization with a slurry containing iron oxide particles and removing residual iron oxide particles after CMP with an organic acid, such as oxalic acid or acetic acid, or a dilute inorganic acid, such as hydrochloric, boric or fluoroboric acid.

The formation and/or growth of dendrites emanating from Cu or Cu alloy lines into a bordering open dielectric field are prevented or substantially reduced by chemically removing a portion of the surface from the dielectric field and from between the lines after CMP. Embodiments include removing up to 20 .ANG. of silicon oxide by buffing with a solution containing ammonium fluoride, diammonium hydrogen citrate, triammonium citrate, a surfactant and de-ionized water.

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San Jose, CA, United States of America

Diana M Schonauer