Selective Dry Etching of HfO2 in CF4 and Cl2/HBr-Based Chemistries. Export

@article{15, abstract = {We investigated HfO2 etching characteristics in conventional Si gate etching chemistries, namely, CF4 and Cl2/HBr/O2-based chemistries. We obtained an adequate etch rate of 2.0 nm/min for both chemistries and a selectivity of 1.9 over SiO2 for Cl2/HBr/O2-based chemistry. We examined the etch rate dependence on source power, bias power, O2 flow rate, and Cl2 flow rate in the Cl2/HBr/O2 chemistry. It was clarified that a physical component is dominant in HfO2 etching in this chemistry. The possibilities of achieving a higher HfO2/SiO2 selectivity and of controlling the anisotropic/isotropic component in HfO2 patterning were also discussed. Moreover, it was clarified that the surface portion of the damaged layer created by the dry-etching step can be removed by a subsequent wet etching. Based on these results, the sub-100 nm patterning of poly-Si/HfO2 gate stacks was successfully demonstrated.}, author = {Maeda, Takeshi and Ito, Hiroyuki and Mitsuhashi, Riichiro and Horiuchi, Atsushi and Kawahara, Takaaki and Muto, Akiyoshi and Sasaki, Takaoki and Torii, Kazuyoshi and Kitajima, Hiroshi}, citeulike-article-id = {558083}, comment = {Empilage : poly-Si (150nm) / HfO2 (par ALD 3-7 nm) / SiO2 (1nm) / Si Commentaires : Gravure en 3 \'{e}tapes : * ME avec CF4 (100 sccm, Ps = 500W, Pbias = 40W, 0.53Pa = 4mTorr) Step a * Cl2/HBr/O2 (40 sccm/30sccm/5sccm, Ps = 350W, Pbias = 100W, 2.7Pa = 20mTorr) Step b * HF dilu\'{e} dans H2O (1\%) CF4 permet de former une couche protectrice sur les flancs du poly-Si. ER (SiO2) est important avec Step a. ER (HfO2) > ER (SiO2) avec Step b. Gravure sans r\'{e}sidus obtenue en modifiant Step b : Ajout de N2 = 15sccm, Ps = 300W au lieu de 350W, pression de 2 Pa = 15mTorr eu lieu de 2.7 Pa L'augmentation de O2 permet de diminuer la gravure de SiO2. Les d\'{e}g\^{a}ts dus \`{a} la gravure plasma peuvent \^{e}tre supprim\'{e}s gr\^{a}ce \`{a} une gravure humide \`{a} base de HF dilu\'{e} }, journal = {Japanese Journal of Applied Physics}, keywords = {cf4, cl2, damage, dhf, dry-etching, gate-patterning, hbr, hfo2, high-k, wet-etching}, month = {April}, number = {4B}, pages = {1864--1868}, posted-at = {2006-03-21 07:54:24}, priority = {0}, title = {Selective Dry Etching of HfO2 in CF4 and Cl2/HBr-Based Chemistries.}, volume = {43}, year = {2004} }

TY - JOUR ID - 15 L3 - citeulike-article-id:558083 N2 - We investigated HfO2 etching characteristics in conventional Si gate etching chemistries, namely, CF4 and Cl2/HBr/O2-based chemistries. We obtained an adequate etch rate of 2.0 nm/min for both chemistries and a selectivity of 1.9 over SiO2 for Cl2/HBr/O2-based chemistry. We examined the etch rate dependence on source power, bias power, O2 flow rate, and Cl2 flow rate in the Cl2/HBr/O2 chemistry. It was clarified that a physical component is dominant in HfO2 etching in this chemistry. The possibilities of achieving a higher HfO2/SiO2 selectivity and of controlling the anisotropic/isotropic component in HfO2 patterning were also discussed. Moreover, it was clarified that the surface portion of the damaged layer created by the dry-etching step can be removed by a subsequent wet etching. Based on these results, the sub-100 nm patterning of poly-Si/HfO2 gate stacks was successfully demonstrated. IS - 4B JF - Japanese Journal of Applied Physics EP - 1868 TI - Selective Dry Etching of HfO2 in CF4 and Cl2/HBr-Based Chemistries. VL - 43 SP - 1864 KW - cf4 KW - cl2 KW - damage KW - dhf KW - dry-etching KW - gate-patterning KW - hbr KW - hfo2 KW - high-k KW - wet-etching N1 - Empilage : poly-Si (150nm) / HfO2 (par ALD 3-7 nm) / SiO2 (1nm) / Si Commentaires : Gravure en 3 étapes : * ME avec CF4 (100 sccm, Ps = 500W, Pbias = 40W, 0.53Pa = 4mTorr) Step a * Cl2/HBr/O2 (40 sccm/30sccm/5sccm, Ps = 350W, Pbias = 100W, 2.7Pa = 20mTorr) Step b * HF dilué dans H2O (1%) CF4 permet de former une couche protectrice sur les flancs du poly-Si. ER (SiO2) est important avec Step a. ER (HfO2) > ER (SiO2) avec Step b. Gravure sans résidus obtenue en modifiant Step b : Ajout de N2 = 15sccm, Ps = 300W au lieu de 350W, pression de 2 Pa = 15mTorr eu lieu de 2.7 Pa L’augmentation de O2 permet de diminuer la gravure de SiO2. Les dégâts dus à la gravure plasma peuvent être supprimés grâce à une gravure humide à base de HF dilué AU - Maeda, Takeshi AU - Ito, Hiroyuki AU - Mitsuhashi, Riichiro AU - Horiuchi, Atsushi AU - Kawahara, Takaaki AU - Muto, Akiyoshi AU - Sasaki, Takaoki AU - Torii, Kazuyoshi AU - Kitajima, Hiroshi PY - 2004/04// ER -