摘要 |
A negative ion etching process is described for etching a substrate, where the negative ions are sputtered from a target by a sputtering gas. The negative ions are released from the target and are accelerated toward the substrate, which they strike as either negative ions or energetic neutrals. The improvement adds an inhibiting substance (hydrogen) to the sputtering gas to dramatically affect the etch rates of the substrate. In one example, the ratio of the etch rates of Si and SiO2 are changed by large amounts by the addition of hydrogen to a sputtering gas comprising an inert species, such as argon.
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