2011A1765

BL46XUHAXPES ࡟ࡼࡿࢤ࣮ࢺ⤯⦕⭷/In-Ga-Zn-O ⭷⏺㠃ࡢ㟁Ꮚ≧ែศᯒCharacterization of electronic state of gate dielectric/In-Ga-Zn-O interface
by HAXPESᏳᒃ 㯞⨾ a, ᑠᕝ ៅ࿃ a, ᐑ⏣ ὒ᫂ a, ➉⏣ ṇ᫂ a, 㐲⸨ ு a, ྜྷᕝ㏱ b, ᒸ ఙே b, 㔜㔛 ᭷୕ b
Asami Yasuia, Shingo Ogawaa, Hiroaki Miyataa, Masaaki Takeda a, Ryo Endo a,Toru Yoshikawa b, Nobuto Oka b, Yuzo Shigesato baᰴᘧ఍♫ᮾࣞࣜࢧ࣮ࢳࢭࣥࢱ࣮, b 㟷Ꮫ኱⌮ᕤa
Toray Research Center Inc.,b
Graduate School of Science and Engineering, Aoyama Gakuin Universityᐇ 㦂 ᐊ ⣔ ࡢ X ⥺ග㟁Ꮚศග㻔XPS㻕ࡼࡾࡶ᳨ฟ῝ࡉࡀ῝࠸◳ X ⥺ග㟁Ꮚศග㻔HAXPES㻕࡟ࡼࡾࠊ20 nm ࡢ⤯⦕⭷ᡂ⭷ᚋࡢ In-Ga-Zn-O㻌 㻔IGZO㻕⭷㻔SiO2/IGZO, SiNx/IGZO㻕࡟ࡘ࠸࡚ࠊ⤯⦕⭷㉺ࡋ࡟㠀◚ቯ࡛⤯⦕⭷࡜ IGZO ⭷⏺㠃㏆ഐࡢඖ⣲ࡢ໬Ꮫ≧ែ࠾ࡼࡧ IGZO ⭷ࡢ౯㟁Ꮚᖏࢆㄪ࡭ࡓࠋ⤯⦕⭷ࡀ SiO2 ⭷ࡢሙྜࡣࠊSiO2/IGZO ⏺㠃ࡢ౯㟁Ꮚᖏୖ➃ࡢ〈‽఩࡟ኚ໬ࡣ⏕ࡌ࡞࠸ࡀࠊ⤯⦕⭷࡟ SiNx⭷ࢆ⏝࠸ࡿ࡜ࠊSiNx/IGZO ⏺㠃࡛〈‽఩ࡀቑ኱ࡍࡿࡇ࡜ࡀ☜ㄆࡉࢀࡓࠋ〈‽఩ᙉᗘࡣࠊ࢟ࣕࣜ࢔㍺㏦≉ᛶ࡟ᙳ㡪ࢆཬࡰࡍ࡜⪃࠼ࡽࢀࡿࡓࡵࠊᮏ◊✲࠿ࡽࢤ࣮ࢺ⤯⦕⭷ࡢ✀㢮࡜ TAOS ࢆ⏝࠸ࡓ TFT≉ᛶࡢ㛵ಀࢆ HAXPES ࡟ࡼࡾ᫂ࡽ࠿࡟࡛ࡁࡿྍ⬟ᛶࡀ♧ࡉࢀࡓࠋ
࣮࣮࢟࣡ࢻ㸸  IGZOࠊinterfaceࠊ◳ X ⥺ග㟁ᏊศගࠊHAXPES⫼ᬒ࡜◊✲㸸
㏱᫂࢔ࣔࣝࣇ࢓ࢫ㓟໬≀༙ᑟయ㻔Transparent Amorphous Oxide Semiconductor:TAOS㻕࡛࠶ࡿ࢔ࣔࣝࣇ࢓ࢫ
In-Ga-Zn-O㻔a-IGZO㻕⭷ࡣࠊᐊ ᡂ⭷࡛ࡶ㟁Ꮚ⛣ືᗘࡀ 10 cm2/Vs ⛬ᗘࢆ♧ࡍࡇ࡜࠿ࡽḟୡ௦ TFT ࡢࢳࣕࢿࣝᮦᩱ࡜ࡋ࡚᭷ຊどࡉࢀ࡚࠸ࡿࠋࡲࡓࠊa-IGZO ⭷ࡣ 3.0 eV ௨ୖࡢ࣡࢖ࢻࢠࣕࢵࣉࢆ᭷ࡋྍどග࡟ᑐ
ࡋ㏱࡛᫂࠶ࡿࡓࡵࠊ㏱᫂࡞ࣇࣞ࢟ࢩࣈࣝࢹࣂ࢖ࢫ࡬ࡢ㐺⏝ࡶᮇᚅࡉࢀ࡚࠸ࡿࠋa-IGZO ⭷ࢆ⏝࠸ࡓ TFT࡛ࡣࠊࢤ࣮ࢺ⤯⦕⭷࡜ࡋ࡚ SiO2 ⭷ࡸ Si3N4 ⭷࡞࡝ࡀ⏝࠸ࡽࢀࠊⰋዲ࡞ TFT ≉ᛶࡶ୍㒊ሗ࿌ࡉࢀ࡚࠸ࡿࠋࡋ࠿ࡋ࡞ࡀࡽࠊ〇㐀ᕤ⛬࡟࠾ࡅࡿᡂ⭷᫬ࡢ㞺ᅖẼࡸᡂ⭷✀࡟ࡼࡾࠊa-IGZO ⭷ࡢ≧ែኚ໬㸦㑏ඖ㸧ࡸỈ⣲ᣑᩓ࡟ࡼࡿప᢬ᢠ໬࡞࡝ࠊTFT ≉ᛶࡀᝏ໬ࡍࡿࡇ࡜ࡶሗ࿌ࡉࢀ࡚࠾ࡾࠊᐇ⏝໬࡟࠾ࡅࡿၥ㢟ࡶ⏕ࡌ࡚࠸ࡿࠋࡑࡢࡓࡵ᭱㐺࡞ࢹࣂ࢖ࢫస〇᮲௳ࡢᣦ㔪ࢆᚓࡿࡓࡵ࡟ࠊ⌧ᅾᵝࠎ࡞◊✲ࡀ㐍ࡵࡽࢀ࡚࠸ࡿࠋࡇࡇ࡛ࠊࢤ࣮ࢺ⤯⦕⭷࡜ࢳࣕࢿࣝ㻔a-IGZO ⭷㻕ࡢ⏺㠃ࡢ≧ែࡣ TFT ≉ᛶ࡟ᙉࡃᙳ㡪ࢆཬࡰࡍࡓࡵࠊ⏺㠃ࡢᵓ㐀ࡸ㟁Ꮚ≧ែࢆヲࡋࡃㄪ࡭ࡿࡇ࡜ࡣᴟࡵ࡚㔜せ࡛࠶ࡿࡀࠊᩘ༑ nm ࡢࢤ࣮ࢺ⤯⦕⭷ࢆᡂ⭷ࡋࡓᚋ࡟ࠊ⏺
㠃ࡢ᝟ሗࢆ┤᥋ⓗ࡟ᚓࡿࡇ࡜ࡣ㏻ᖖࡢᐇ㦂ᐊࣞ࣋ࣝࡢศᯒ࡛ࡣ㞴ࡋ࠸ࠋᮏ◊✲࡛ࡣࠊ㏻ᖖࡢ㌾ X ⥺ XPS ࡟ẚ࡭᳨࡚ฟ῝ࡉࡀ῝࠸◳ X ⥺ග㟁Ꮚศගἲ㸦᳨ฟ῝ࡉᩘ༑ nm㸧ࢆ⏝࠸࡚ࠊa-IGZO ⭷ୖ࡟ 20nm ࡢࢤ࣮ࢺ⤯⦕⭷ࢆᙧᡂࡋࡓヨᩱ࡟ᑐࡋࠊ㌾ X ⥺࡛ࡣㄪ࡭ࡿࡇ࡜ࡀ࡛ࡁ
࡞࠸ࢤ࣮ࢺ⤯⦕⭷/a-IGZO ⭷⏺㠃ࡢ໬Ꮫ≧ែ࠾ࡼࡧ㟁Ꮚ≧ែࢆホ౯ࡋࡓࠋᐇ㦂㸸Si ᇶᯈ࡟ DC ࣐ࢢࢿࢺࣟࣥࢫࣃࢵࢱἲ࡟࡚⣙ 300nm ཌࡢ IGZO ⭷ࢆᡂ⭷ᚋࠊRF ࣐ࢢࢿࢺࣟࣥࢫࣃࢵࢱἲ࡟࡚⣙ 20 nm ཌࡢ⤯⦕⭷㸦SiO2 ⭷ࡲࡓࡣ SiNx ⭷㸧ࢆᙧᡂࡋࡓࠋ࡞࠾ࠊIGZO ⭷ᡂ⭷࠿ࡽ⤯⦕⭷ᡂ⭷ࡲ࡛඲࡚┿✵୰࡟࡚ᐇ᪋ࡋࡓࠋࡇࢀࡽࡢヨᩱ࡟ᑐࡋࠊSPring-8 BL46XU ࡟࡚◳ X ⥺ග㟁Ꮚศග㻔hȤ=7.9 keV㻕ࢆ㐺⏝ࡋࡓࠋග㟁Ꮚ᳨ฟゅᗘࡣࠊ80r㸦ヨᩱἲ⥺᪉ྥ᳨ࠝฟゅᗘࡀ᭱ࡶ῝࠸ࠞࢆ 90r࡜ࡍࡿ㸧࡟タᐃࡋࡓࠋ

⤖ᯝ࠾ࡼࡧ⪃ᐹ㸸
IGZOࠊ
SiO2/IGZOࠊSiNx/IGZO ࡢ O1s ࠾ࡼࡧ SiNx/IGZO ࡢ N1s ࢫ࣌ࢡࢺࣝࢆᅗ 1 ࡟♧ࡍࠋ⤯⦕⭷/IGZOᵓ㐀ヨᩱ࡟ࡘ࠸࡚ࠊO1s ࡲࡓࡣ N1s ࢫ࣌ࢡࢺࣝ࠿ࡽྛ⤯⦕⭷࡟⏤᮶ࡍࡿᡂศࡀㄆࡵࡽࢀࠊO1s ࢫ࣌ࢡࢺࣝ࠿ࡽ IGZO ⭷࡟⏤᮶ࡍࡿᡂศ㸦531 eV ௜㏆㸧ࡀㄆࡵࡽࢀࡓࠋࡇࡢࡇ࡜࠿ࡽࠊ⤯⦕⭷ࡀ 20 nm Ꮡᅾࡋ࡚࠸࡚ࡶࠊ⤯⦕⭷㉺ࡋ࡟ IGZO ࡢ໬Ꮫ≧ែࠊ㟁Ꮚ≧ែࡀホ౯࡛ࡁࡿࡇ࡜ࡀศ࠿ࡗࡓࠋ
࡞࠾ࠊ
SiNx/IGZOࡢ O1s ࡟࠾ࡅࡿ 531 eV ࡢࣆ࣮ࢡࡢ㧗⤖ྜ࢚ࢿࣝࢠ࣮ഃࡢ⫪ᵓ㐀ࡣࠊ
SiNx ⭷ࡢ⾲㠃ࡶࡋࡃࡣ SiNx/IGZO⏺㠃ࡢ㓟໬࡟⏤᮶ࡍࡿ࡜⪃࠼ࡽࢀࡿࠋࡲࡓࠊ඲ヨᩱࡢ IGZO ⭷ࢆᵓᡂࡍࡿᡂศ㸦In, Ga ࠾ࡼࡧ Zn㸧ࡢෆẆࣆ࣮ࢡ఩⨨㸦ࢹ࣮ࢱࡣᮍᥖ㍕㸧ࡣࠊᩥ⊩್࡞࡝࠿ࡽุ᩿ࡋ࡚ IGZO ⭷ࡢ In, Ga ࠾ࡼࡧ Zn ࡢࣆ࣮ࢡ఩⨨࡜ࡋ࡚ጇᙜ࡛࠶ࡾࠊヨᩱ㛫࡛㢧ⴭ࡞㐪࠸ࡣㄆࡵࡽࢀ࡞࠿ࡗࡓࠋ
IGZOࠊSiO2/IGZOࠊSiNx/IGZO ࡢ౯㟁Ꮚᖏࢫ࣌ࢡࢺࣝࢆᅗ 2 ࡟♧ࡍࠋ౯㟁Ꮚᖏୖ➃࡟࠾ࡅࡿ〈‽఩ᙉᗘ㸦ᅗ୰▮༳㸧࡟ࡘ࠸࡚ࠊSiO2/IGZO ࡢ〈‽఩ᙉᗘࡣ IGZO ࡜ẚ࡭࡚㢧ⴭ࡞㐪࠸ࡀㄆࡵࡽࢀ࡞࠸ࡀࠊ
SiNx/IGZO ࡢ〈‽఩ᙉᗘࡣ IGZO ࠾ࡼࡧ SiO2/IGZO ࡜ẚ࡭࡚㧗࠸ഴྥࡀㄆࡵࡽࢀࡓࠋࡇࢀࡣࠊIGZO⭷ࡢୖ㒊࡟ᙧᡂࡍࡿ⤯⦕⭷ࡢ✀㢮࡟ࡼࡾࠊIGZO ⭷ࡢ⏺㠃ࡢ㟁Ꮚ≧ែࡀኚ໬ࡍࡿࡇ࡜ࢆ♧၀ࡍࡿ⤖ᯝ࡛࠶ࡿࠋࢤ࣮ࢺ⤯⦕⭷࡟ SiNx ⭷ࢆ⏝࠸ࡿࡇ࡜࡛ SiO2 ⭷ࡼࡾ㧗࠸ㄏ㟁⋡࡜ప࠸࣮ࣜࢡ㟁ὶࡀᮇᚅ࡛ࡁࡿࡀࠊ〈‽఩ᙉᗘࡣ࢟ࣕࣜ࢔㍺㏦≉ᛶ࡟ᙳ㡪ࢆཬࡰࡍ࡜⪃࠼ࡽࢀࡿࡓࡵࠊࢤ࣮ࢺ⤯⦕⭷ࡢ✀㢮࡜ TAOS ࢆ⏝࠸ࡓ TFT ≉ᛶࡢ㛵ಀࢆ⣔⤫ⓗ࡟ᢕᥱࡍࡿᚲせࡀ࠶ࡿࠋᮏ◊✲ࡣ HAXPES ࡀୖグࡢ㛵ಀࢆ᫂ࡽ࠿࡟࡛ࡁࡿ᭷ຊ࡞ࢶ࣮ࣝ࡜࡞ࡿྍ⬟ᛶࡀ࠶ࡿࡇ࡜ࢆ♧ࡋ࡚࠸ࡿࠋ㻝㻚㻜㻿㼕㻻㻞㻺㻝㼟㼔䃜㻩㻣㻚㻥㻌㼗㼑㼂㻔㻮㻸㻠㻢㼄㼁㻕㻵㼚㻙㻻㻘㻌㻳㼍㻙㻻㻘㻌㼆㼚㻙㻻㻵㻳㼆㻻㻿㼕㻻㻞㻛㻵㻳㼆㻻㻿㼕㻺㼤㻛㻵㻳㼆㻻㻜㻚㻤㻜㻚㻢㻜㻚㻠㻜㻚㻞㻝㻚㻜㻜㻚㻜㻺㼕㼠㼞㼕㼐㼑㻿㼕㻺㼤㻛㻵㻳㼆㻻㻜㻚㻤㻜㻚㻢㻜㻚㻠㻭㼙㼙㼛㼚㼕㼡㼙㻌㻿㼍㼘㼠㻜㻚㻞㻜㻚㻜㻡㻠㻞㻡㻟㻣㻡㻟㻞㻮㼕㼚㼐㼕㼚㼓㻌㼑㼚㼑㼞㼓㼥㻌㻔㼑㼂㻕㻡㻞㻣㻡㻞㻞㻠㻜㻥㻠㻜㻠㻟㻥㻥㻮㼕㼚㼐㼕㼚㼓㻌㼑㼚㼑㼞㼓㼥㻌㻔㼑㼂㻕㻟㻥㻠㻟㻤㻥ᅗ 1. IGZO, SiO2/IGZO and SiNx/IGZO ࡢ O1s ࢫ࣌ࢡࢺࣝ࠾ࡼࡧSiNx/IGZO ࡢ N1s ࢫ࣌ࢡࢺࣝࠋග㟁Ꮚ᳨ฟゅᗘࡣ 80 q㻝㻚㻞㼂㼍㼘㼑㼚㼏㼑㻌㼎㼍㼚㼐㼔䃜㻩㻣㻚㻥㻌㼗㼑㼂㻔㻮㻸㻠㻢㼄㼁㻕㻝㻚㻜㻵㼚㼠㼑㼚㼟㼕㼠㼥㻌㻔㼍㼞㼎㻚㻌㼡㼚㼕㼠㼟㻕㻵㼚㼠㼑㼚㼟㼕㼠㼥㻌㻔㼍㼞㼎㻚㻌㼡㼚㼕㼠㼟㻕㻝㻚㻞㻻㻝㼟㼔䃜㻩㻣㻚㻥㻌㼗㼑㼂㻔㻮㻸㻠㻢㼄㼁㻕㻵㼚㼠㼑㼚㼟㼕㼠㼥㻌㻔㼍㼞㼎㻚㻌㼡㼚㼕㼠㼟㻕㻝㻚㻞㻵㻳㼆㻻㻿㼕㻻㻞㻛㻵㻳㼆㻻㻿㼕㻺㼤㻛㻵㻳㼆㻻㻜㻚㻤㻜㻚㻢㻜㻚㻠㻜㻚㻞㻜㻚㻜㻤㻢㻠㻞㻮㼕㼚㼐㼕㼚㼓㻌㼑㼚㼑㼞㼓㼥㻌㻔㼑㼂㻕㻜㻙㻞ᅗ 2. IGZO, SiO2/IGZO and SiNx/IGZO ࡢ౯㟁Ꮚᖏࢫ࣌ࢡࢺࣝࠋග㟁Ꮚ᳨ฟゅᗘࡣ 80 q