Method of atomic layer etching of oxide

• Main Authors: SHERPA, SONAM, RANJAN, ALOK
• Format: Patent
• Language: Chinese; English
• Published: 21.05.2023
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

In one exemplary embodiment, described herein is an ALE process for etching an oxide. In one embodiment, the oxide is silicon oxide. The ALE modification step includes the use of a carbon tetrafluoride (CF4) based plasma. This modification step preferentially removes oxygen from the surface of the silicon oxide, providing a silicon rich surface. The ALE removal step includes the use of a hydrogen (H2) based plasma. This removal step removes the silicon enriched monolayer formed in the modification step. The silicon oxide etch ALE process utilizing CF4 and H2 steps may be utilized in a wide range of substrate process steps. For example, the ALE process may be utilized for, but is not limited to, self-aligned contact etch steps, silicon fin reveal steps, oxide mandrel pull steps, oxide spacer trim, and oxide liner etch.