Metal‐assisted chemical etching (MacEtch) has shown tremendous success as an anisotropic wet etching method to produce ultrahigh aspect ratio semiconductor nanowire arrays, where a metal mesh pattern serves as the catalyst. However, producing vertical via arrays using MacEtch, which requires a pattern of discrete metal disks as the catalyst, has often been challenging because of the detouring of individual catalyst disks off the vertical path while descending, especially at submicron scales. Here, the realization of ordered, vertical, and high aspect ratio silicon via arrays by MacEtch is reported, with diameters scaled from 900 all the way down to sub‐100 nm. Systematic variation of the diameter and pitch of the metal catalyst pattern and the etching solution composition allows the extraction of a physical model that, for the first time, clearly reveals the roles of the two fundamental kinetic mechanisms in MacEtch, carrier generation and mass transport. Ordered submicron diameter silicon via arrays with record aspect ratio are produced, which can directly impact the through‐silicon‐via technology, high density storage, photonic crystal membrane, and other related applications.
Reactive interface patterning promoted by lithographic electrochemistry serves as a facile method for generating submicron structures on conductive substrates. A binary‐potential step applied to a metal layer with a resist overlayer allows silicon to be patterned with metal oxides. In this study, the role and influence of the resist overlayer on the uniformity of pattern formation are examined. The ability of the resist to detach from the underlying metal is a critical determinant of pattern geometry. By choosing an appropriate resist, large patterns with submicron precision are generated quickly by the application of the binary‐potential steps. From this information, a lithography‐free approach to generating identical patterns is achieved with simple resists such as that furnished from a lacquer–water emulsion, thus greatly simplifying the patterning of silicon with metal oxide catalysts.
more » « less- PAR ID:
- 10075309
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Small
- Volume:
- 14
- Issue:
- 41
- ISSN:
- 1613-6810
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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