In-Situ Passivation for Nonlinear Optical Crystals

A system for passivating nonlinear optical (NLO) crystal defects, comprising:

• a hermetically-sealed exposure chamber including an enclosure configured to contain a volume of purge gas within an internal cavity;
• a nonlinear optical (NLO) crystal housed within the internal cavity of the hermetically-sealed exposure chamber, wherein the NLO crystal is passivated by the purge gas contained within the hermetically-sealed exposure chamber;
• at least one laser source configured generate and transmit a laser beam of a selected wavelength through the NLO crystal, wherein the NLO crystal is configured to generate a converted laser beam of a harmonic wavelength through frequency conversion during passivation of the NLO crystal;
• and
• a sample stage configured to secure a sample, wherein the sample is configured to receive at least a portion of the converted laser beam of the harmonic wavelength.

A system for passivating nonlinear optical (NLO) crystal defects, comprising:

• a purge gas subsystem including a sealed purge gas pump, wherein the purge gas subsystem operates at a selected purge gas pressure, wherein the sealed purge gas pump is configured to recirculate purge gas through the purge gas subsystem at a selected flow rate;
• an exposure chamber fluidically coupled to the purge gas subsystem via a purge gas inflow port and a purge gas outflow port, wherein the purge gas is configured to flow through the exposure chamber at the selected flow rate;
• a nonlinear optical (NLO) crystal housed within the exposure chamber, wherein the NLO crystal is passivated by the purge gas as the purge gas flows through the exposure chamber;
• at least one laser source configured generate and transmit a laser beam of a selected wavelength through the NLO crystal, wherein the NLO crystal is configured to generate a converted laser beam of a harmonic wavelength through frequency conversion during passivation of the NLO crystal;
• and
• a sample stage configured to secure a sample, wherein the sample is configured to receive at least a portion of the converted laser beam of the harmonic wavelength.

A method for passivating nonlinear optical (NLO) crystal defects comprising:

• pumping a purge gas through an exposure chamber including a nonlinear optical (NLO) crystal;
• transmitting a laser beam of a selected wavelength into the exposure chamber;
• converting the laser beam of the selected wavelength to a converted laser beam of a harmonic wavelength;
• passivating the NLO crystal during conversion to the converted laser beam of the harmonic wavelength while the purge gas flows through the exposure chamber;
• and
• transmitting the converted laser beam of the harmonic wavelength from the exposure chamber.

A method for passivating nonlinear optical (NLO) crystal defects comprising:

• pumping a purge gas into an exposure chamber including a nonlinear optical (NLO) crystal;
• hermetically sealing the exposure chamber at a selected pressure;
• transmitting a laser beam of a selected wavelength into the exposure chamber;
• converting the laser beam of the selected wavelength to a converted laser beam of a harmonic wavelength;
• passivating the NLO crystal during conversion to the converted laser beam of the harmonic wavelength while the exposure chamber is hermetically sealed;
• and
• transmitting the converted laser beam of the harmonic wavelength from the exposure chamber.

A method for passivating nonlinear optical (NLO) crystal defects comprising:

• pumping a purge gas through an exposure chamber including a nonlinear optical (NLO) crystal at a selected purge gas pressure;
• transmitting a laser beam of a selected wavelength into the exposure chamber;
• converting the laser beam of the selected wavelength to a converted laser beam of a harmonic wavelength;
• passivating the NLO crystal during conversion to the converted laser beam of the harmonic wavelength while the purge gas flows through the exposure chamber;
• recirculating the purge gas in a purge gas system fluidically coupled to the exposure chamber during conversion to the converted laser beam of the harmonic wavelength;
• and
• transmitting the converted laser beam of the harmonic wavelength from the exposure chamber.

A system for characterizing a semiconductor device, comprising:

• a laser system, comprising:
• an exposure chamber;
• a nonlinear optical (NLO) crystal housed within the exposure chamber, wherein the nonlinear optical crystal is sufficiently passivated to establish a selected passivation level;
• and
• at least one laser source configured generate and transmit a laser beam of a selected wavelength through the NLO crystal, wherein the NLO crystal is configured to generate a converted laser beam of a harmonic wavelength through frequency conversion during passivation of the NLO crystal;
• a sample stage configured to secure a sample, wherein the laser system is configured to illuminate at least a portion of a surface of the sample with the converted laser beam of the harmonic wavelength;
• one or more detectors configured to receive at least a portion of illumination transmitted by the surface of the sample;
• and
• a controller, wherein the controller includes one or more processors and memory configured to store one or more sets of program instructions, wherein the one or more processors are configured to execute the one or more sets of program instructions, wherein the one or more sets of program instructions are configured to cause the one or more processors to:
• obtain one or more images of the sample from the one or more detectors;
• and
• determine the presence or absence of one or more defects in the one or more images of the sample.

A method for characterizing a semiconductor device comprising:

• converting a laser beam of a selected wavelength to a converted laser beam of a harmonic wavelength via a nonlinear optical (NLO) crystal;
• passivating the NLO crystal during conversion to the converted laser beam of the harmonic wavelength;
• transmitting the converted laser beam of the harmonic wavelength onto a surface of a sample;
• obtaining one or more images of the sample;
• and
• determining the presence or absence of one or more defects in the one or more images of the sample.