Ion-enhanced chemical etching of HfO[sub 2] for integration in metal--oxide--semiconductor field effect transistors

@article{citeulike:514149, abstract = {High-density chlorine plasmas were used to chemically etch HfO2, a promising high dielectric constant material, where the etch rate scaled up linearly with the square root of ion energy at energies above 50 eV. Higher etch rates were obtained at lower pressures and high microwave powers, where the electron temperature and ion densities were high. Optical emission spectroscopy and quadrupole mass spectrometry were used to identify the etching products, which are mainly highly chlorinated hafnium (HfCl3 and HfCl4) and ClO. Surface chlorination was confirmed after etching was confirmed by x-ray photoelectron spectroscopy. The addition of BCl3 in the Cl2 plasmas was found to significantly enhance the HfO2 etch rate and improve the etching selectivity to Si from \~{}0.01 in a pure Cl2 plasma to \~{}0.9 in a pure BCl3 plasma at an ion energy of 75 eV. The etching selectivity was improved to 4 as the ion energies reduced towards the etching threshold energy in a pure BCl3 plasma. BCl3 plasmas were found effective in patterning HfO2 for fabricating the metal\&\#150;oxide\&\#150;semiconductor field effect transistors, enabling a complete removal of HfO2 from the source and drain regions yielding high electron mobility. \©2003 American Vacuum Society.}, author = {Sha, Lin and Puthenkovilakam, Ragesh and Lin, You S. and Chang, Jane P. }, citeulike-article-id = {514149}, doi = {http://dx.doi.org/10.1116/1.1627333}, journal = {Journal of Vacuum Science \& Technology B: Microelectronics and Nanometer Structures}, keywords = {dielectric, hfo2, high-k}, number = {6}, pages = {2420--2427}, posted-at = {2006-02-21 09:36:28}, priority = {2}, publisher = {AVS}, title = {Ion-enhanced chemical etching of HfO[sub 2] for integration in metal--oxide--semiconductor field effect transistors}, url = {http://dx.doi.org/10.1116/1.1627333}, volume = {21}, year = {2003} }

TY - JOUR ID - citeulike:514149 L3 - citeulike-article-id:514149 TI - Ion-enhanced chemical etching of HfO[sub 2] for integration in metal--oxide--semiconductor field effect transistors JF - Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures VL - 21 IS - 6 SP - 2420 EP - 2427 PB - AVS N2 - High-density chlorine plasmas were used to chemically etch HfO2, a promising high dielectric constant material, where the etch rate scaled up linearly with the square root of ion energy at energies above 50 eV. Higher etch rates were obtained at lower pressures and high microwave powers, where the electron temperature and ion densities were high. Optical emission spectroscopy and quadrupole mass spectrometry were used to identify the etching products, which are mainly highly chlorinated hafnium (HfCl3 and HfCl4) and ClO. Surface chlorination was confirmed after etching was confirmed by x-ray photoelectron spectroscopy. The addition of BCl3 in the Cl2 plasmas was found to significantly enhance the HfO2 etch rate and improve the etching selectivity to Si from ~0.01 in a pure Cl2 plasma to ~0.9 in a pure BCl3 plasma at an ion energy of 75 eV. The etching selectivity was improved to 4 as the ion energies reduced towards the etching threshold energy in a pure BCl3 plasma. BCl3 plasmas were found effective in patterning HfO2 for fabricating the metal–oxide–semiconductor field effect transistors, enabling a complete removal of HfO2 from the source and drain regions yielding high electron mobility. ©2003 American Vacuum Society. KW - dielectric KW - hfo2 KW - high-k AU - Sha, Lin AU - Puthenkovilakam, Ragesh AU - Lin, You AU - Chang, Jane PY - 2003/// UR - http://dx.doi.org/10.1116/1.1627333 ER -