Method for measuring peak carrier concentration in ultra-shallow junctions
AssigneeKLA-Tencor Corporation
InventorsAlex Salnik, Lena Nicolaides, Jon Opsal, Mira Bakshi
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Abstract
A method is disclosed for determining peak carrier concentration in ultra shallow junctions of semiconductor samples. A region of the surface of the sample is periodically excited. The effects of the excitation are monitored by a probe beam. Synchronous detection produces in-phase (I) and quadrature (Q) signals. These signals are compared to signals obtained from calibration samples to evaluate peak carrier concentration.
Claims9
A method of determining peak carrier concentration in an ultra shallow junction formed on a semiconductor sample comprising the steps of:
- periodically exciting a region on the surface of the sample;
- directing a probe beam to reflect off the region on the sample being periodically excited;
- monitoring the periodic changes in the reflected probe beam and generating output signals in response thereto;
- analyzing the output signals with a phase synchronous detection system and generating in-phase (I) and quadrature (Q) signals corresponding thereto;
- and
- comparing the Q and I signals with reference signals to determine the peak carrier concentration of the ultra shallow junction.
A method of determining peak carrier concentration and junction depth in an ultra shallow junction formed on a semiconductor sample comprising the steps of:
- periodically exciting a region on the surface of the sample;
- directing a probe beam to reflect off the region on the sample being periodically excited;
- monitoring the periodic changes in the reflected probe beam and generating output signals in response thereto;
- analyzing the output signals with a phase synchronous detection system and generating in-phase (I) and quadrature (Q) signals corresponding thereto;
- and
- comparing the Q and I signals with Q and I reference signals obtained from a set of calibration reference samples to determine the peak carrier concentration and junction depth of the ultra shallow junction.
Dependencies are inferred from the claim text.