Real-time detection of particulate matter during deposition chamber manufacturing

A system comprising:

• a process chamber;
• one or more light sources to generate:
• a first incident beam of light, wherein the first incident beam of light illuminates a region of the process chamber, and
• a second incident beam of light, wherein the second incident beam of light improves uniformity of illumination of at least a part of the illuminated region of the process chamber compared with uniformity of illumination of the part of the illuminated region of the process chamber by the first incident beam of light, the first incident beam of light having intensity that decreases along a direction within the region of the process chamber and the second incident beam of light having intensity that increases along the direction within the region of the process chamber;
• a light detector to:
• collect light scattering data characterizing scattered light produced by one or more particles, individual particles being illuminated simultaneously by both the first incident beam of light and the second incident beam of light;
• and
• a processing device communicatively coupled to the light detector, the processing device to:
• determine, based on the light scattering data, a distribution of the one or more particles in the process chamber.

A method comprising:

• illuminating, using a first incident beam of light, a region of a process chamber;
• obtaining scattering data comprising an intensity map of scattered light for at least a portion of the illuminated region, the scattered light produced upon interaction of the first incident beam of light with particles in the illuminated region, wherein the intensity map comprises a background portion and a plurality of maxima;
• determining, using the background portion of the intensity map, a density of plasma-forming particles of a first size in the illuminated region;
• and
• determining, using the plurality of maxima of the intensity map, a density of contaminant particles of a second size in the illuminated region.