Dog bone exhaust slit tunnel for processing chambers

A processing chamber, comprising:

• a chamber body, wherein the chamber body comprises:
• a first side;
• a second side opposite the first side;
• an upper window having an optically transparent window;
• and
• a base, wherein the first side, the second side, the upper window and the base define and enclose a thermal processing region;
• a gas injectors disposed adjacent the first side, wherein the gas injectors is configured to introduce a processing gas into the thermal processing region;
• and
• an exhaust slit assembly disposed adjacent to the second side, the exhaust slit assembly comprising:
• an opening exposed to the thermal processing region, the opening having a center and outer edges, the center of the opening and outer edges of the opening vertically defined between the upper window and the base, and wherein an outer height at the outer edges of the opening is at least 30% larger in a vertical direction than a center height at the center of the opening, and wherein the opening has a rectangular shape at the outer edges and is curved through the center between the outer edges.