Browse Prior Art Database

Poly uniformity improvement using GICB Technique

IP.com Disclosure Number: IPCOM000236623D
Publication Date: 2014-May-06
Document File: 2 page(s) / 53K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a technique called Gas Ion Cluster Beam (GICB) for surface modification and uniformity improvement across the wafer.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 01 of 2

Poly uniformity improvement using GICB Technique

Gate height variation is a critical technology problem for enabling Replacement Metal Gate (RMG) Fin field effect transistors (Finfet). RMG Finfet requires dummy gate planarity <5nm over various fin densities. The current process uses Chemical Mechanical Planarization (CMP) to planarize poly across Fin and no-Fin areas. The within wafer (WIW) uniformity being achieved by the process is ~12nm.

The novel contribution is a technique called Gas Ion Cluster Beam (GICB) for surface modification and uniformity improvement across the wafer. The technique comprises the following methods:

1. Conventional CMP process to reduce local topography 2. Measure Si thickness variation on the entire wafer to discover high and low spots 3. Cluster ion beam to reduce wafer non-uniformity of Si thickness 4. Optionally, use touch-up CMP or wet clean to smooth or remove beam damaged surface

Figure 1: Deposit a-Si

Figure 2: Showing:


 Post a-Si CMP


 WIW uniformity ~ 10nm still need improvement

Figure 3: Showing:


 Gas Ion Cluster Beam Location Specific Processing (GCIB LSP)


 Surface modification - etching the top areas


 Correcting the WIW non-uniformity

1


Page 02 of 2

Figure 4: Example Embodiment

2