METHOD AND DEVICE FOR MONITORING PLASMA-CHEMICAL ETCHING PROCESSES USING DIFFERENTIAL OPTICAL ACTINOMETRY Russian patent published in 2005 - IPC

FIELD: manufacture of semiconductor devices in micro- and nanoelectronics.

SUBSTANCE: real-time monitoring of plasma-chemical etching processes using differential optical actinometry includes mixing of gas-source of chemically active particles and inert gas-actinometer complying with optical actinometry conditions in definite proportion; their supply to reactor chamber followed by measurement of intensities of chemically active particle (chemical agent) emission line in surface reaction and emission line of gas-actinometer in plasma in the course of plasma-chemical etching in plasma-chemical reactor according to algorithm of monitoring actinometric rate-of-layer etching, process selectivity, and end-of-etching moment; in the process mixture of gas-source of chemically active particles and gas-actinometer prepared in advance is supplied to one gas admission channel; used as controlled variable is signal controlling normalization of actinometer emission line intensity at which differential signal between emissive intensities of chemically active agent or particle in surface etching reaction and gas-actinometer on characteristic wavelength from plasma volume tends to zero.

EFFECT: ability of monitoring layer rate-of-etching, selectivity, and end-of-etching moment , including structures having small area of windows in mask.

2 cl, 1 dwg