Predictive control of the plasma processes in the OLED display mass production referring to the discontinuity qualifying PI-VM

Abstract

Metal target dry etching process applied for the organic light emitting diode display manufacturing is hard to control without the generation of the defect particles. A large amount of the metal-halide by-prodcucts with the non-volatile physical nature are produced in the large area plasma-assisted process chamber. To achieve high-density plasma-based throughput, the inductively coupled plasma type dry etchers were adopted for large-area display manufacturing processes. However, this type of plasma source causes the ion flux-driven damages on the chamber inner walls near the RF power supplied antenna. Sputtered Al atoms from the ceramic parts or etching targets were redeposited onto the chamber inner walls after they form the metal-halide compounds. Redeposited by-prodcucts have very high binding energies to decompose. Undecomposed layers were stuck on the chamber inner wall and flaked off later to form the defect particles. To control this undesired phenomenon, decomposition reaction activated—and plasma locality controlled—two types of ISDs (In Situ Dry cleanings) were designed. A more appropriate type of ISD had selected referring to the developed PI-VM (Plasma Information based Virtual Metrology) model, which qualifies the start of mass production after the discontinuities of the process. The big data set of equipment engineering system and optical emission spectroscopy, accumulated during the mass production, were parameterized to the PI parameters and were applied to the PI-VM modeling. Management of the mass production with the designed ISD and PI-VM model could reduce the 25% of defect particle driven yield loss.