Methods for forming multilayer structures on a substrate and related multilayer structures

A method for depositing a multilayer structure on a substrate, the method comprising:

• seating a substrate on a substrate support disposed in a chamber body, the chamber body having an upper wall and a lower wall;
• heating the substrate to a deposition temperature employing at least an upper heater element array supported above the upper wall of the chamber body;
• providing a controller in communication with at least the upper heater element array, wherein the controller throttles power to at least the upper heater element array according to a set of optical temperature measurements communicated to the controller from at least a first pyrometer and a second pyrometer, the first pyrometer and the second pyrometer being supported above the upper heater element array and being optically coupled to a surface of the substrate over a first acquisition area and a second acquisition area, wherein the second acquisition area is radially distal from the first acquisition area;
• and
• depositing a multilayer structure over the substrate employing a multiphase deposition process which includes at least three deposition phases comprising;
• epitaxially depositing a first SiGe:B layer over the substrate during a first deposition phase;
• epitaxially depositing a fully strained second SiGe:B layer directly over the first SiGe:B layer during a second deposition phase;
• and
• epitaxially depositing a Si:B layer directly on the fully strained second SiGe:B layer,
• wherein the boron concentration (atom/cm3) non-uniformity in the first SiGe:B layer, the fully strained second SiGe:B layer, and the Si:B layer is less than 3%.