Etching of High-k Dielectric HfO2 Films in BCl3-Containing Plasmas Enhanced with O2 Addition Export

@article{44, abstract = {Etching characteristics of high dielectric constant HfO2 films have been studied in high-density BCl3-containing plasmas without rf biasing. Emphasis was placed on plasma conditions and etch chemistries to achieve a high selectivity over Si and SiO2 and to enhance the etch rates. The HfO2 etch rate was ∼5 nm/min at a pressure P0=10 mTorr in a BCl3 plasma, giving a selectivity of >10 over Si and SiO2. At lower P0 ≤ 6 mTorr in BCl3, the deposition of boron-chlorine compounds BxCly was observed on all sample surfaces of HfO2, Si, and SiO2 to inhibit etching. The addition of O2 to BCl3 was found to suppress the deposition and significantly enhance the HfO2 etch rate, which was ∼50 nm/min at P0=5 mTorr in a BCl3/30\%-O2 plasma; at higher O2 addition ≥40\%, the heavy deposition of boron-oxygen compounds BxOy occurred on surfaces to inhibit etching. The mechanisms underlying the phenomena observed are discussed based on plasma and surface diagnostics.}, author = {Kitagawa, Tomohiro and Nakamura, Keisuke and Osari, Kazushi and Takahashi, Kazuo and Ono, Kouichi and Oosawa, Masanori and Hasaka, Satoshi and Inoue, Minoru}, citeulike-article-id = {558627}, comment = {Empilage : HfO2 (CVD sans recuit, 50nm) Commentaires: A faible pression (< 6mTorr), on a un d\'{e}p\^{o}t de BxCly sur la surface bloquant la gravure. L'ajout d'O2 permet de supprimer ce d\'{e}p\^{o}t et d'augmenter l'ER de HfO2. L'ajout d'O2 va r\'{e}duire la concentration des esp\`{e}ces BClx, supprimant ainsi la formation de la couche passive BxCly \`{a} la surface qui emp\^{e}che la gravure. L'exc\`{e}s d'O2 va entra\^{i}ner la formation de solide B2O3 : 2BCl3 + 3O => B2O3 + 6Cl }, journal = {Japanese Journal of Applied Physics}, keywords = {bcl3-o2, ecr, hfo2, high-k}, number = {10}, pages = {L297--L300}, posted-at = {2006-03-21 14:13:03}, priority = {0}, title = {Etching of High-k Dielectric HfO2 Films in BCl3-Containing Plasmas Enhanced with O2 Addition}, volume = {45}, year = {2006} }

TY - JOUR ID - 44 L3 - citeulike-article-id:558627 N2 - Etching characteristics of high dielectric constant HfO2 films have been studied in high-density BCl3-containing plasmas without rf biasing. Emphasis was placed on plasma conditions and etch chemistries to achieve a high selectivity over Si and SiO2 and to enhance the etch rates. The HfO2 etch rate was ∼5 nm/min at a pressure P0=10 mTorr in a BCl3 plasma, giving a selectivity of >10 over Si and SiO2. At lower P0 ≤ 6 mTorr in BCl3, the deposition of boron-chlorine compounds BxCly was observed on all sample surfaces of HfO2, Si, and SiO2 to inhibit etching. The addition of O2 to BCl3 was found to suppress the deposition and significantly enhance the HfO2 etch rate, which was ∼50 nm/min at P0=5 mTorr in a BCl3/30%-O2 plasma; at higher O2 addition ≥40%, the heavy deposition of boron-oxygen compounds BxOy occurred on surfaces to inhibit etching. The mechanisms underlying the phenomena observed are discussed based on plasma and surface diagnostics. IS - 10 JF - Japanese Journal of Applied Physics EP - L300 TI - Etching of High-k Dielectric HfO2 Films in BCl3-Containing Plasmas Enhanced with O2 Addition VL - 45 SP - L297 KW - bcl3-o2 KW - ecr KW - hfo2 KW - high-k N1 - Empilage : HfO2 (CVD sans recuit, 50nm) Commentaires: A faible pression (< 6mTorr), on a un dépôt de BxCly sur la surface bloquant la gravure. L’ajout d’O2 permet de supprimer ce dépôt et d’augmenter l’ER de HfO2. L’ajout d’O2 va réduire la concentration des espèces BClx, supprimant ainsi la formation de la couche passive BxCly à la surface qui empêche la gravure. L’excès d’O2 va entraîner la formation de solide B2O3 : 2BCl3 + 3O => B2O3 + 6Cl AU - Kitagawa, Tomohiro AU - Nakamura, Keisuke AU - Osari, Kazushi AU - Takahashi, Kazuo AU - Ono, Kouichi AU - Oosawa, Masanori AU - Hasaka, Satoshi AU - Inoue, Minoru PY - 2006/// ER -