Sample Preparation Method to Measure Strain of P-Channel with Esige by Nano Beam Diffraction

The quantitatively analysis of embedded SiGe (eSiGe) strain was performed by nano beam diffraction (NBD). We have confirmed the best condition of sample preparation for the NBD measurement for strained p-MOSFET. The thickness of sample must be thick enough to prevent stress relaxation by electron beam.

 As a result, we could obtain very stable strain variation ±0.1% at unstrained silicon(Si) region.

We also found that damaged layer caused by focused ion beam (FIB) milling process have a crucial role

in the NBD measurement.

 Thus, low energy FIB milling condition was optimized for reducing surface damaged layer of the

specimen. We have found the best sample conditions, thickness above 260nm and low energy FIB milling

for sample preparation.

I. INTRODUCTION

II. EXPERIMENTAL

III. RESULTS AND DISCUSSIONS

3.1 Strain relaxation on sample thickness

3.2 Strain sensitivity related to damaged layer

3.3 Strain profile at p-channel with eSiGe

‡W. Conclusion