Patent ID: 7893703
Filing Date: 2011-02-22
Classification: G01R,H01L

Abstract:
1. A system configured to control deposition of a charge on a wafer for measurement of one or more electrical properties of the wafer, comprising: a corona source configured to deposit the charge on the wafer, wherein the corona source comprises a needle disposed within a discharge chamber, wherein the discharge chamber and the needle are disposed within a housing of the corona source, wherein the corona source further comprises one or more shielding components disposed within the housing and around the discharge chamber such that the discharge chamber is within the one or more shielding components, wherein the corona source is configured to generate a plasma in the discharge chamber such that the plasma is generated within the one or more shielding components, and wherein the one or more shielding components are configured to prevent interaction between the plasma and components of the corona source; a sensor configured to measure one or more conditions within the corona source, wherein the one or more conditions comprise one or more properties of two or more chemical species in the corona source during deposition of the charge on the wafer; one or more gas flow devices coupled to the corona source, wherein the one or more gas flow devices comprise one or more mixing chambers coupled to an inlet of the corona source, and wherein the one or more mixing chambers are configured to mix the two or more chemical species prior to introduction of the two or more chemical species to the corona source; and a control subsystem configured to alter one or more parameters of the corona source based on the one or more conditions.