An Updated Ion Polishing System for Tem Specimen Preparation of Materials

Abstract

AbstractThe construction and performance of an improved ion milling instrument are described. The updated instrument is based upon an earlier version fixed low angle ion milling system. The updated system employs two improved guns having the ability of independent variable milling angle adjustment, while operating at high voltage in the vacuum system. The milling rate of these ion guns is typically ≈ 90μm/hr/gun pair for copper at 5keV and 10°. Designed to compliment the variable angle ion gun is a new specimen holder which permits low angle double sided milling. The combination of these two features offers numerous single or double sided milling conditions to facilitate the production of higher quality TEM specimens in less time. The range of ion gun angles encompassed is 0° to 10° for single-sided milling and 0° to ± 10° for double-sided milling. The instrument also incorporates an electronic mechanism to generate directional sector milling which benefits primarily the production of cross sectional TEM specimens and heat sensitive materials since the ion guns are turned off for a portion of time during each revolution. Another new feature of the instrument is chemical ion milling which facilitates the preparation of certain compound semiconductors. The ability of this improved ion milling instrument for rapid ion polishing and improved specimen quality is demonstrated by a number of TEM images of metals, ceramics and semiconductors.