Systems and Methods for Improving Planarity using Selective Atomic Layer Etching (ALE)

A method for planarizing a patterned substrate in a spatial atomic layer processing system, the method comprising:

• providing the patterned substrate on a rotating platen of the spatial atomic layer processing system, wherein one or more features formed on the patterned substrate have higher regions and lower regions;
• spinning the rotating platen;
• exposing a surface of the patterned substrate to a precursor gas to form a modified layer on the patterned substrate, wherein a rotational speed of the rotating platen causes the modified layer to be preferentially formed on the higher regions of the one or more features;
• removing the modified layer so that the higher regions of the one or more features are preferentially etched as compared to the lower regions of the one or more features;
• and
• repeating the steps of exposing a surface of the patterned substrate to a precursor gas to form a modified layer and removing the modified layer to gradually reduce a height of the one or more features until a desired planarization of the one or more features is achieved, wherein the desired planarization reduces a height differential between the higher regions and the lower regions by at least 25%.

A method for operating an atomic layer processing system to planarize a patterned substrate, the method comprising:

• providing at least a first layer as part of the patterned substrate, wherein the first layer comprises at least a portion of one or more features formed on the patterned substrate, wherein the one or more features have higher regions and lower regions, and wherein a height differential exists between the higher regions and the lower regions;
• providing the patterned substrate in the atomic layer processing system;
• forming a modified layer on the first layer, at least one step of the forming the modified layer on the first layer being exposing a surface of the first layer to a first precursor gas to produce the modified layer, wherein the modified layer being preferentially formed onto the higher regions of the one or more features as compared to the lower regions of the one or more features;
• removing the modified layer,
• wherein the forming the modified layer on the first layer and the removing the modified layer preferentially etches the higher regions of the one or more features as compared to the lower regions of the one or more features so as to lessen the height differential between the higher regions of the one or more features and the lower regions of the one or more features;
• and
• utilizing a controller to control at least one operating parameter of the atomic layer processing system to achieve a desired amount of planarization of the patterned substrate.

An atomic layer processing system configured to planarize a patterned substrate, comprising:

• a spatial atomic layer processing chamber comprising a rotating platen;
• a sensor that provides sensor data related to a property of the patterned substrate and/or a reaction in the spatial atomic layer processing chamber;
• and
• a controller, the controller coupled to the sensor to receive the sensor data, the controller configured to utilize the sensor data to adjust at least one operating parameter of the atomic layer processing system so as to achieve a desired amount of planarization of the patterned substrate