異方性ウエットエッチングを用いた溝型ゲートMOSトランジスタの作製

• Project/Area Number: 14750266
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Single-year Grants
• Research Field: 電子デバイス・機器工学
• Research Institution: Kyushu University
• Principal Investigator: 池田 晃裕 九州大学, 大学院・システム情報科学研究院, 助手 (60315124)
• Project Period (FY): 2002 – 2004
• Project Status: Completed (Fiscal Year 2004)
• Budget Amount: ¥3,100,000 (Direct Cost: ¥3,100,000); Fiscal Year 2004: ¥1,000,000 (Direct Cost: ¥1,000,000); Fiscal Year 2003: ¥1,100,000 (Direct Cost: ¥1,100,000); Fiscal Year 2002: ¥1,000,000 (Direct Cost: ¥1,000,000)
• Keywords: Recessed channle MOSFET / Anisotropic wet etching / Short channle effect / Plasma oxidation / nitridation / P on P++エピタキシャルウエハ / 溝型ゲートMOSトランジスタ / ショートシャネル効果 / 低温プラズマ酸化,窒化 / V-grooved gate / KOH / short channel effect / MOSFET

Research Abstract

P on P^+エピウエハを用いて,異方性ウエットエッチングを用いた溝型ゲートMOSトランジスタを作製し,特性の評価を行った.KOHエッチングマスクのSiO2はEB露光とICPプラズマエッチングによりパターンニングを行った.最小ゲート長は0.2umであった.その電子移動度は,約60cm^2/V・secであった.ゲート絶縁膜にはプラズマ酸化/窒化膜を用いた.ゲート絶縁膜は,Coxの測定から6nm程度であった.酸化のみのゲート絶縁膜に比べて,プラズマ窒化によりリーク電流が凡そ半分に減らせることが確認された.しかし,SiON/Si界面準位は10^11/cm^2台と通常の平面上のSiO2/Si界面と比べてかなり大きいことが分かった.また,ゲート絶縁膜の絶縁破壊電圧分布を調べたところ,窒化酸化膜で凡そ7MV/cmと低い位置にピークを持つことが分かった.KOHエッチング面のSiON/Si界面準位が多いことが主な原因であると考えられる.今回得られた移動度は,一般的な平面型MOSFETのそれに比べてかなり低い.その原因についてSiON/Si界面の界面準位が高いことに加えて,ドレイン・基板間pn接合の逆バイアスリーク電流が非常に大きいことが影響していることが分かった.今回ソース・ドレイン接合はスピンコートしたPSG(リンガラス)膜からのRTAによる個相拡散を用いているが,リン以外の不要な不純物も拡散してしまったと考えられる.また,この方法では,0.5um以下の浅い接合を形成することもできなかった.イオン注入など精密に制御されたリークの少ないpn接合の形成により,さらなるMOSFET特性の改善が期待されると思われる.

Research Products

• [Journal Article] A Recessed Channel MOSFET with Plasma-grown Silicon Oxynitride Gate Dielectric (2005)
  • Author(s): Rohana Perera, Akihiro Ikeda, Yukinori Kuroki
  • Journal Title: Research Reports on Information Science and Electrical Engineering of Kyushu University Vol.10, No.1(to be published)
  • NAID: 110001131570
• [Journal Article] A Study of the Reliability of MOSFETs in Two Stacked Thin Chips for 3D System in Package (2005)
  • Author(s): A.Ikeda, Y.Kuroki, et al.
  • Journal Title: Proceeding of 43rd IEEE Reliability Physics Symposium (to be published)
• [Journal Article] Simulated Characteristics of Deep-submicrometer Recessed Channel epi-MOSFETs (2004)
  • Author(s): Rohana Perera, Akihiro Ikeda, Yukinori Kuroki
  • Journal Title: Research Reports on Information Science and Electrical Engineering of Kyushu University Vol.9, No.2 Pages: 67-72
  • NAID: 110000948899
• [Journal Article] Recessed Channel MOSFET Using Low Temperature Plasma Gate Oxide on P on P+ Epitaxial Si Wafer (2004)
  • Author(s): Akihiro Ikeda, Rohana Perera, Yukinori Kuroki
  • Journal Title: Abstract of 7th Asia Pacific Conference on Plasma Science and Technology & 17th Symposium on Plasma Science for Materials Pages: 76-76
• [Journal Article] Design and Measurements of Test Element Group Wafer Thinned to 10μm for 3D System in Package (2004)
  • Author(s): Akihiro Ikeda, et al.
  • Journal Title: Proc.IEEE Internal Conference on Microelectronic Test Structures Vol.17 Pages: 161-164
• [Journal Article] Mass-production fabrication of miniaturized plastic chip devices for biochemical applications (2004)
  • Author(s): T.Fujimura, A.Ikeda, et al.
  • Journal Title: Proceeding of Device and Process Technologies for MEMS, Microelectronics, and Photonics III Vol.5276 Pages: 392-399
• [Publications] Rohana Perera, Akihiro Ikeda, Reiji Hattori, Yukinori Kuroki: "Effects of post annealing on removal of defect states in silicon oxynitride films grown by oxidation of silicon substrates nitrided in inductively coupled nitrogen plasma"Thin Solid Films. Vol.423 No.2. 212-217 (2003)
• [Publications] Rohana Perera, Akihiro Ikeda, Reiji Hattori, Yukinori Kuroki: "Trap assisted leakage current conduction in thin silicon oxynitride films grown by rapid thermal oxidation combined microwave excited plasma nitridation"Microelectronic Engineering. Vol.65 No.4. 357-370 (2003)
• [Publications] Rohana Perera, Akihiro Ikeda, Reiji Hattori, Yukinori Kuroki: "Anomalous Leakage Current in Silicon Oxynitride Thin Films Grown by Microwave Excited Nitrogen Plasma Nitridation"Proceedings of 7th International Conference on Properties and Applications of Dielectric Materials, IEEE Dielectrics and Electrical Insulation Society. Vol.3. 1084-1087 (2003)
• [Publications] Rohana Perera, Akihiro Ikeda, Reiji Hattori, Yukinori Kuroki: "Effects of post annealing on removal of defect states in silicon oxynitride films grown by oxidation of silicon substrates nitrided in inductively coupled nitrogen plasma"Thin Solid Films. Vol.423,No.2. 212-217 (2003)
• [Publications] Rohana Perera, Akihiro Ikeda, Reiji Hattori, Yukinori Kuroki: "Trap assisted leakage current conduction in thin silicon oxynitride films grown by rapid thermal oxidation combined microwave excited plasma nitridation"Microelectronic Engineering. (to be published). (2003)
• [Publications] Rohana Perera, Akihiro Ikeda, Reiji Hattori, Yukinori Kuroki: "Anomalous Leakage Current in Silicon Oxynitride Thin Films Grown by Microwave Excited Nitrogen Plasma Nitridation"Proceedings of IEEE 7th International Conference on Properties and Applications of Dielectric Materials 2003. (to be published). (2003)