Patent · US Active

Etching method to form spacers having multiple film layers

US9378975B2 · kind B2 · utility

6Cited by
0References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 6, 2015
Grant dateJun 28, 2016
Priority date—
Expiry dateFeb 6, 2035

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01L21/31105
  • WIPO fieldSemiconductors
  • WIPO sectorElectrical engineering

Abstract

Methods herein can be used for removing silicon nitride around fins and other structures without damaging underlying silicon structures. Methods herein also include forming dual layer spacers and L-shaped spacers, as well as other configurations. Techniques include a multi-step process of anisotropic etching of low-k material with high selectivity to silicon nitride, followed by isotropic etching of SiN with high selectivity to the low-k material. Such techniques, for example, can be used to form an L-shaped spacer on a 3-D gate structure, as well as providing a method for completely removing silicon nitride without damaging surrounding or underlying materials.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.