The role of inhibitors during electrodeposition of thin metallic films

Technical Report · Tue May 01 04:00:00 EDT 1990

OSTI ID:5778368

Armstrong, M J ^[1]

---

1. California Univ., Berkeley, CA (USA). Dept. of Chemical Engineering Lawrence Berkeley Lab., CA (USA)

The role of brightening agents during the deposition of thin metal films was analyzed. The model brightening system studied was copper deposition in the presence of benzotriazole (BTA). Emphasis was placed on the early stages of deposition. The development of microtopography was characterized with in situ scanning tunneling microscopy. Cuprous-BTA film formation was measured with impedance spectroscopy. Copper electrochemistry was measured with double-pulse potentiometry. The incorporation of BTA, including the effects of mass transport conditions, was studied with x-ray photoelectron spectroscopy and secondary ion mass spectroscopy. A visual survey of deposits from 0.5 M CuSO{sub 4}, 0.5 M H{sub 2}SO{sub 4} indicated that brightening occurs when the concentration of BTA is greater than 100 {mu}M and the current density is greater than 50 mA/cm{sup 2}. A passive layer was found to form during cathodic polarization of copper in 0.5 M CuSO{sub 4}, 0.5 M H{sub 2}SO{sub 4} with 100 and 200 {mu}M BTA. Following breakdown of the passive layer, with increased polarization, the copper remains covered with a BTA film with a coverage following Langmuir adsorption kinetics. Benzotriazole was not incorporated into the copper deposits. The nucleation site density of Cu on Pt was only a function of overpotential irrespective of the BTA concentration. The presence of BTA increases the overpotential (resulting in an increase in nucleation rate) for a given current density which results in a decreased particle size. Benzotriazole altered the morphology of the deposited Cu. Deposits from BTA free electrolyte consisted of flat planes terminated with ledges with growth occurring at the ledges. Deposits from BTA containing electrolyte consisted of hemispheres with growth occurring uniformly on the surface.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5778368
• Report Number(s): LBL-28972; ON: DE90014177
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101* -- Metals & Alloys-- Preparation & Fabrication
AMINES
AMINO ACIDS
AROMATICS
AZO COMPOUNDS
AZO DYES
CARBOXYLIC ACIDS
COPPER
COUMARIN
DEPOSITION
DYES
ELECTRODEPOSITION
ELECTROLYSIS
ELECTRON SPECTROSCOPY
ELEMENTS
ESTERS
FILMS
FLUORESCEIN
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROXY ACIDS
HYDROXY COMPOUNDS
INDICATORS
LACTONES
LYSIS
METALS
METHYL RED
NUCLEATION
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PHENOLS
PHOTOELECTRON SPECTROSCOPY
PLATING
POLYPHENOLS
PYRANS
REAGENTS
RHODAMINES
SPECTROSCOPY
SURFACE COATING
THIN FILMS
TRANSITION ELEMENTS