Wafer processing equipment having exposable sensing layers

A particle monitoring device, comprising:

• a wafer substrate including wafer electronics and a support surface;
• a first micro sensor mounted on the support surface, wherein the first micro sensor includes a first mask layer over a first sensing layer;
• and
• a second micro sensor mounted on the support surface, wherein the second micro sensor includes a second mask layer over a second sensing layer;
• wherein the first micro sensor and the second micro sensor have respective parameters and include respective sensor surfaces on the respective sensing layers, and wherein the respective parameters change when material is removed from the respective sensor surfaces.

A method, comprising:

• initiating a wafer fabrication process in a process chamber having a chamber volume, wherein a first micro sensor and a second micro sensor are disposed within the process chamber, and wherein a first sensing layer of the first micro sensor and a second mask layer of the second micro sensor are exposed to the chamber volume;
• etching a first sensor surface on the first sensing layer of the first micro sensor by an etchant;
• and
• stripping the second mask layer of the second micro sensor to expose a second sensor surface on a second sensing layer of the second micro sensor to the chamber volume.