Efficient Process for Direct Atomic Layer Deposition of Metallic Cu Thin Films Based on an Organic Reductant

Tripurari S. Tripathi, Maarit Karppinen*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

15 Citations (Scopus)
232 Downloads (Pure)

Abstract

We report a promising approach to use an organic reductant for in situ atomic layer deposition (ALD) of metallic copper films. The process is based on sequentially pulsed precursors copper acetyl acetonate (acac), water, and hydroquinone (HQ) and yields crystalline copper films at temperatures as low as <200 °C with an appreciably high deposition rate of ∼2 Å/cycle. Deposition parameters are explored for the process m × [n × (Cu(acac)2-H2O)-HQ] with several values of m and n, keeping m×n fixed to 500. The films are found crystalline with metallic copper as the main phase, but different trace amounts of Cu2O are observed when the HQ pulse frequency decreases below 1/5. The as-deposited copper films are shiny and specularly reflecting and show metallic-type electrical conductivity. The absolute resistivity of the films estimated at room temperature is in the order of 2-5 µO cm, having a sizable contribution, with 0.5 µO cm from residual resistivity as a result of impurities and/or imperfections. We believe that the new process could yield benefits in interconnect applications.

Original languageEnglish
Pages (from-to)1230-1235
Number of pages6
JournalChemistry of Materials
Volume29
Issue number3
DOIs
Publication statusPublished - 14 Feb 2017
MoE publication typeA1 Journal article-refereed

Fingerprint Dive into the research topics of 'Efficient Process for Direct Atomic Layer Deposition of Metallic Cu Thin Films Based on an Organic Reductant'. Together they form a unique fingerprint.

Cite this