Patent ID: 6124927
Filing Date: 2000-09-26
Classification: G01J,H01J

Abstract:
A method of detecting the endpoint of cleaning of a polycrystalline silicon etch chamber of a dry polycrystalline silicon etching system said system comprising chamber walls and chamber components which include insulative components and conducting and semiconducting components, wherein said polycrystalline silicon etching chamber has at least one observation window within said chamber walls, comprising:mounting an optical light filtering apparatus in line with said observation window and on the outside of said dry polycrystalline silicon etch chamber whereby said optical light filtering apparatus is sensitive to passing electromagnetic energy generated by Si--F components of a plasma contained within said polycrystalline silicon etching chamber with a wavelength of optical emission within the range between about 430 and 460 nm;mounting an optical light intensity measurement apparatus in line with said optical light filtering apparatus whereby said optical light intensity measurement apparatus is sensitive to measuring electromagnetic energy generated by Si--F components of a plasma contained within said polycrystalline silicon etching chamber with a wavelength of optical emission within the range between about 430 and 460 nm;monitoring intensity of said optical light radiating through said window using said light filtering apparatus further using said optical light intensity measurement apparatus; and terminating said cleaning of said polycrystalline silicon etching chamber at a point in time where said intensity of optical light radiating through said window has reached a certain level.