X⥺ࢺ࣏ࢢࣛࣇ࢕࣮ࢆ⏝࠸ࡓ⇕໬Ꮫ࢚ࢵࢳࣥࢢฎ⌮࡟ࡼࡿ4H-SiC༢⤖ᬗᇶᯈ⾲㠃ࡢᇶᗏ㠃㌿఩࠿ࡽ㈏㏻ล≧㌿఩࡬ࡢኚ᥮ᣲືࡢほᐹ㫽ぢ ⪽, ⠛ཎṇேᮾὒⅣ⣲ᰴᘧ఍♫᮶ࡢ࢙࢘ࣁ௙ୖࡆຍᕤᡭἲ࡛࠶ࡿ໬ᏛᶵᲔ◊☻

1. ࡣࡌࡵ࡟༙ᑟయSiC࢚ࣆࢱ࢟ࢩ࢙ࣕࣝ࢘ࣁ୰࡟ྵࡲࢀࡿᇶᗏ

㸦Chemical Mechanical Polishing : CMP㸧࡜ẚ㍑ࡋ

㠃㌿఩㸦Basal Plane Dislocation : BPD㸧ࡣࠊࣂ࢖࣏࣮࡚࢚ࣆࢱ࢟ࢩࣕࣝᡂ㛗᫬࡟BPD࠿ࡽTED࡬ࡢኚ᥮⋡ࣛືసࡍࡿࢹࣂ࢖ࢫ࡟࠾࠸࡚㡰᪉ྥ㏻㟁᫬࡟ࢩࣥࢢࡀ㧗ࡃ[8]ࠊKOH࢚ࢵࢳࣆࢵࢺἲ㸦◚ቯホ౯ἲ㸧࡟ࡼࡾࣝࢩࣙࢵࢡ࣮ࣞᆺࡢ✚ᒙḞ㝗࡬ᣑᙇࡋ࡚㡰᪉ྥຎ໬

SiCᇶᯈෆ㒊ࡢ఩⨨࡛ࡢBPD࠿ࡽTED࡬ࡢኚ᥮ࢆ♧࡜࿧ࡤࢀࡿ࢜ࣥ㟁ᅽࡢቑ኱ࢆࡶࡓࡽࡍ[1]ࠋSiCᇶᯈ୰၀ࡍࡿ⤖ᯝ[9]ࡀᚓࡽࢀ࡚࠸ࡿࠋ

ࡢBPDࡣ࢖ࣥࢦࢵࢺ⤖ᬗᡂ㛗᫬࡟ᙧᡂࡉࢀࡿࡶࡢ࡛ࠊ

ᮏሗ࿌࡛ࡣࠊSi⵨Ẽᅽ࢚ࢵࢳࣥࢢἲ࡟ࡼࡿSiCᇶᯈ࢚ࣆࢱ࢟ࢩࣕࣝᡂ㛗᫬࡟ࡑࡢ࡯࡜ࢇ࡝ࡀ࢚ࣆ/ᇶᯈ⏺

⾲㠃࡛ࡢBPDኚ᥮ຠᯝࢆ┤᥋☜ㄆࡋࠊ᭦࡟ࡑࡢኚ᥮ᣲ㠃 ࡛ ↓ ᐖ ࡞ ㈏ ㏻ ล ≧ ㌿ ఩ 㸦 Threading Edgeືࢆ⌮ゎࡍࡿࡇ࡜ࢆ┠ⓗ࡜ࡋ࡚ࠊSi⵨Ẽᅽ࢚ࢵࢳࣥࢢ

Dislocation : TED㸧࡟ኚ᥮ࡉࢀࡿࡓࡵ[2]ࠊ࢚ࣆࢱ࢟

ฎ⌮๓ᚋ࡟࠾ࡅࡿ4H-SiCᇶᯈ⾲㠃ࡢBPDࡢᙧែࡢኚ

ࢩࣕࣝ⭷୰࡬ఏ᧛ࡍࡿBPD࡟㉳ᅉࡍࡿ㡰᪉ྥຎ໬ࡣ໬࡞ࡽࡧ࡟࢚ࣆࢱ࢟ࢩࣕࣝᡂ㛗ᚋࡢ࢚ࣆࢱ࢟ࢩࣕࣝ᤼㝖ྍ⬟࡛࠶ࡿࠋࡋ࠿ࡋ࡞ࡀࡽࠊ㧗㟁ὶᐦᗘ࡛ࡢ㏻㟁⭷୰࡬ࡢ㌿఩ఏ᧛ᣲືࢆ㠀◚ቯ࠿ࡘ㧗ศゎ⬟ほᐹྍ᮲௳ୗ࡛ࡣ࢚ࣆࢱ࢟ࢩࣕࣝ⭷ࡼࡾࡉࡽ࡟῝࠸࢚ࣆ/ᇶ⬟࡞ᨺᑕග࡟ࡼࡿX⥺ࢺ࣏ࢢࣛࣇ࢕࣮ࢆ⏝࠸࡚ホ౯ࡋᯈ⏺㠃࡟ࡲ࡛฿㐩ࡍࡿ㐣๫࢟ࣕࣜ࢔ࡀᇶᯈ୰ࡢBPDࡓࠋࢆ✚ᒙḞ㝗࡬ᣑᙇࡉࡏ࡚㡰᪉ྥຎ໬ࢆᘬࡁ㉳ࡇࡍࡇ࡜ࡀሗ࿌ࡉࢀ࡚࠸ࡿ[3]ࠋ୍᪉ࠊBPDࡢTED࡬ࡢኚ᥮఩

2. ᐇ㦂

⨨ࡀ࢚ࣆ/ᇶᯈ⏺㠃ࡼࡾࡉࡽ࡟῝࠸ᇶᯈෆ㒊࡟࠶ࡿሙホ౯ヨᩱ࡜ࡋ࡚ CMP ௙ୖࡆࡉࢀࡓᕷ㈍ࡢ 4 ࢖ࣥࢳྜࠊࡑࡢ῝ࡉ࡟ᑐᛂࡋ࡚✚ᒙḞ㝗ࢆᣑᙇࡉࡏࡿ㟁ὶᐦ

4H-SiC㸦0001㸧4r࢜ࣇ Si 㠃࣋࢔࢙࢘ࣁ 2 ᯛ㸦ヨᩱᗘࡀ㧗ࡃ࡞ࡿࡇ࡜ࡀሗ࿌ࡉࢀ࡚࠾ࡾ[4]ࠊᇶᯈ୰ࡢBPDձ࠾ࡼࡧղ㸧ࢆ౪ࡋࡓࠋࡇࡢ࡜ࡁ࢙࢘ࣁෆࡢ㌿఩ᐦᗘࢆ࢚ࣆࢱ࢟ࢩࣕࣝᡂ㛗๓࡟ᇶᯈෆ㒊࡛ணࡵTED࡬✚ࢆ࡞ࡿ࡭ࡃྠࡌ᮲௳࡛ẚ㍑ࡍࡿࡓࡵ࡟ྠ୍࢖ࣥࢦࢵ

ᴟⓗ࡟ኚ᥮ࡉࡏࡿࡇ࡜ࡀ࡛ࡁࢀࡤࠊ㡰᪉ྥຎ໬ࡢᢚไ

ࢺ࠿ࡽษࡾฟࡉࢀࡓ࢙࢘ࣁࢆ⏝࠸ࡓࠋヨᩱࡢฎ⌮᮲௳࡟᭷ຠ࡞ᡭἲࡢ୍ࡘ࡜࡞ࡿ࡜⪃࠼ࡽࢀࡿࠋ࡞ࡽࡧ࡟ホ౯ᕤ⛬ࢆ⾲ 1 ࡟♧ࡍࠋSi ⵨Ẽᅽ࢚ࢵࢳࣥࢢ

ࡑࡇ࡛ᡃࠎࡣ࢚ࣆࢱ࢟ࢩࣕࣝᡂ㛗๓ࡢ᪂ࡓ࡞SiC⾲ࡣࠊฎ⌮ ᗘ 2000Υࡢࡶ࡜࢚ࢵࢳࣥࢢ㝖ཤ㔞࡟ᑐࡍ㠃ฎ⌮ἲ࡜ࡋ࡚ࠊ⇕໬Ꮫ࢚ࢵࢳࣥࢢ࡜࡞ࡿSi⵨Ẽᅽࡿ㌿఩ኚ᥮ᣲືࡢᕪࡢ᭷↓ࢆ☜ㄆࡍࡿࡓࡵ࡟ヨᩱձ࢚ࢵࢳࣥࢢἲ[5-6]࡟╔┠ࡋ࡚࠸ࡿࠋSi⵨Ẽᅽ࢚ࢵࢳࣥࢢ࡜ղ࡛ពᅗⓗ࡟␗࡞ࡿ Si ⵨Ẽᅽ࢚ࢵࢳࣥࢢ㔞ࢆ᪋ࡋἲࡣࠊTaC/Ta」ྜᮦᩱ࠿ࡽ࡞ࡿᆣላᆺᐜჾෆ࡬Si⵨ࡓࠋ࢚ࣆࢱ࢟ࢩࣕࣝᡂ㛗ࡣࠊ⭷ཌ 10 μmࠊࢻ࣮ࣃࣥࢺẼᅽ౪⤥※࡜࡞ࡿSiࢆ௜୚ࡋSiC࢙࢘ࣁࢆ1600㹼

⃰ᗘ㸦❅⣲㸧1×1016 cm-3 ࡢᡂ⭷᮲௳࡛⾜ࡗࡓࠋྛฎ⌮࡛ຍ⇕ࡍࡿࡇ࡜࡛SiC(s)㸩Si(g) →ᕤ⛬๓ᚋࡢ࢙࢘ࣁ⾲㠃ࡢ㌿఩ࡢᣲືࡣࠊ஑ᕞࢩࣥࢡࣟ

Si2C(g)ࡢ࢚ࢵࢳࣥࢢ཯ᛂࢆᚓࡿࠋᮏᡭἲ࡟ࡼࡾSiC࢘ࢺࣟࣥග◊✲ࢭࣥࢱ࣮BL09 ࢆ⏝࠸࡚཯ᑕἲ࡟ࡼࡿᩳ࢙ࣁ⾲㠃࡟ṧᏑࡍࡿ₯യ࡞࡝ࡢຍᕤኚ㉁ᒙࢆ≀⌮ⓗධᑕ X ⥺ࢺ࣏ࢢࣛࣇ࢕࣮㸦ᅇᢡ࣋ࢡࢺࣝ g=11-28㸧ࢆ࡞ࢲ࣓࣮ࢪࣞࢫ࡛㝖ཤࡍࡿ࡜࡜ࡶ࡟ศᏊᒙࢫࢸࢵࣉ

⾜࠸ࠊࢺ࣏ࢢࣛࣇീࢆ X ⥺ࣇ࢕࣒ࣝ࡟᧜ᙳࡋࡓࠋ2200Υࡢ㧗࠿ࡽ࡞ࡿᖹ⁥࡞⾲㠃ࢆᚓࡿࡇ࡜ࡀ࡛ࡁࡿ[7]ࠋࡉࡽ࡟ࠊ
ࡇࢀࡲ࡛ࡢ◊✲࡟ࡼࡗ࡚Si⵨Ẽᅽ࢚ࢵࢳࣥࢢἲࡣᚑ ࡢ㌿఩ᵓ㐀ࡢゎ᫂࡞࡝ࡀࢸ࣮࣐࡜ࡋ࡚ᣲࡆࡽࢀࡿࠋ

⾲ 1 ヨᩱฎ⌮᮲௳࠾ࡼࡧホ౯ᕤ⛬3㸬⤖ᯝཬࡧ⪃ᐹ
ᅗ 1 ࡣࠊヨᩱձࡢྛฎ⌮๓ᚋࡢ BPD ྠⅬ X ⥺ࢺ࣏ࢢࣛࣇീほᐹ౛࡛࠶ࡿࠋᅗ 1(a)ࡢ୸࡛♧ࡉࢀࡓ⟠ᡤࡣ
CMP ⾲㠃࡟࠾ࡅࡿ BPD㸦⥺≧ࢥࣥࢺࣛࢫࢺ㸧ࡢඛ➃㒊ศ࡛࠶ࡿࠋSi ⵨Ẽᅽ࢚ࢵࢳࣥࢢᚋࠊᅗ 1(b)࡟࠾࠸࡚
BPD ࡢඛ➃ࡣ[-1-120]᪉ྥ࡬⣙ 40 μm ⛣ືࡋ࡚࠾ࡾࠊ
࢙࢘ࣁࡢ࢜ࣇゅࡀ 4r࡛࠶ࡿࡇ࡜࠿ࡽ࢚ࢵࢳࣥࢢ㝖ཤ㔞ࡣ⣙ 2.8 μm ࡜᥎ᐃࡉࢀࡿࠋࡲࡓࠊBPD ࡢඛ➃ࡣTED ࢆ♧ࡍẚ㍑ⓗᑠࡉ࠸ⓑⅬᙧ≧ࡢࢥࣥࢺࣛࢫࢺ࡟ኚ໬ࡋ࡚࠸ࡿࠋࡉࡽ࡟࢚ࣆࢱ࢟ࢩࣕࣝᡂ㛗ᚋ࡟࠾࠸࡚ᅗ 1 ヨᩱձࡢ BPD ྠⅬ X ⥺ࢺ࣏ࢢࣛࣇീࠊ(a) CMPࠊࡣᅗ 1(c)࡟♧ࡍ࡜࠾ࡾࠊⓑⅬᙧ≧ࡢࢥࣥࢺࣛࢫࢺࡣ࢚(b) Si ⵨Ẽᅽ࢚ࢵࢳࣥࢢᚋࠊ(c) ࢚ࣆࢱ࢟ࢩࣕࣝᡂ㛗ᚋࣆࢱ࢟ࢩࣕࣝ⭷୰࡟ᘬࡁ⥅ࡀࢀ࡚⥔ᣢࡋ࡚࠾ࡾࠊ࢚ࣆࢱ࢟ࢩࣕࣝ⭷୰࡬ࡢ BPD ఏ᧛㸦[11-20]᪉ྥ࡬ࡢ㌿఩ࡢఙᒎ㸧ࡣぢࡽࢀ࡞࠿ࡗࡓࠋࡲࡓྠᵝ࡟ࠊᅗ 2 ࡣヨᩱղࡢྛฎ⌮๓ᚋࡢ BPD ྠⅬ X ⥺ࢺ࣏ࢢࣛࣇീほᐹ౛࡛࠶ࡿࠋᅗ 2(a)-(b)ࡼࡾࠊ୸࡛♧ࡉࢀࡓ BPD ࡢඛ➃ࡣSi ⵨Ẽᅽ࢚ࢵࢳࣥࢢᚋ࡟[-1-120]᪉ྥ࡬⣙11 μm ⛣ືࡋ࡚࠾ࡾࠊ࢚ࢵࢳࣥࢢ㝖ཤ㔞ࡣ⣙ 0.8 μm ࡜᥎ᐃࡉࢀࡿࠋࡇࡢ࡜ࡁࠊヨᩱղ࡟࠾࠸࡚ࡶ BPD ඛ➃ࡣ Si ⵨Ẽᅽ࢚ࢵࢳࣥࢢᚋ㸦ᅗ 2(b)㸧࡟ TED ࢆ♧ࡍࢥࣥࢺࣛࢫ
ࢺ࡬ኚ໬ࡋ࡚࠾ࡾࠊ࢚ࣆࢱ࢟ࢩࣕࣝᡂ㛗ᚋ㸦ᅗ 2(c)㸧
ࡶ⥔ᣢࡉࢀ࡚࠸ࡿࡇ࡜ࢆ☜ㄆࡋࡓࠋࡇࢀࡽࡢᣲືࡣࠊヨᩱձղࡢ」ᩘ⟠ᡤ࡛ほᐹࡉࢀࡓࡓࡵࠊ2.8 μm ཬࡧ0.8 μm ࡑࢀࡒࢀࡢ␗࡞ࡿ࢚ࢵࢳࣥࢢ㔞᮲௳࡟࠾࠸࡚
ࡶ BPD ኚ᥮ຠᯝࡀྠᵝ࡟ᚓࡽࢀࡿࡇ࡜ࡀ♧ࡉࢀࡓࠋᅗ 2 ヨᩱղࡢ BPD ྠⅬ X ⥺ࢺ࣏ࢢࣛࣇീࠊ(a) CMPࠊ௨ୖࡢ⤖ᯝࡼࡾࠊSi ⵨Ẽᅽ࢚ࢵࢳࣥࢢ⾲㠃࡟࠾ࡅࡿ(b) Si ⵨Ẽᅽ࢚ࢵࢳࣥࢢᚋࠊ(c) ࢚ࣆࢱ࢟ࢩࣕࣝᡂ㛗ᚋ

BPD ඛ➃ࡢ TED ࡬ࡢኚ᥮ᣲືࢆᨺᑕග࡟ࡼࡿ X ⥺ࢺ࣏ࢢࣛࣇ࢕࣮ࢆ⏝࠸ࡿࡇ࡜࡟ࡼࡗ࡚┤᥋ほᐹࡍࡿ

4. ࡲ࡜ࡵࡇ࡜࡟ᡂຌࡋࡓࠋSi ⵨Ẽᅽ࢚ࢵࢳࣥࢢἲ࡟ࡼࡿ SiC

4H-SiC ༢⤖ᬗᇶᯈ⾲㠃ࡢ࢚ࣆࢱ࢟ࢩࣕࣝᡂ㛗๓ࡢ࢙࢘ࣁ⾲㠃ࡢ BPD ኚ᥮⌧㇟ࡣࠊࡑࡢ㧗 ࣉࣟࢭࢫࡢ᪂ࡓ࡞⾲㠃ฎ⌮ἲ࡜ࡋ࡚⇕໬Ꮫ࢚ࢵࢳࣥࢢ࡛࠶ࡿ Si⇕࢚ࢿࣝࢠ࣮[10-11]࡟ࡼࡗ࡚ࡶࡓࡽࡉࢀ࡚࠸ࡿࡶࡢ࡜

⵨Ẽᅽ࢚ࢵࢳࣥࢢἲ࡟╔┠ࡋࠊSi ⵨Ẽᅽ࢚ࢵࢳࣥࢢࡀ⪃࠼ࡽࢀࡿࡀࠊ࢚ࢵࢳࣥࢢ཯ᛂ⎔ቃୗ࡟࠾࠸࡚ࡶኚ᥮

ࡶࡓࡽࡍ SiC ࢙࢘ࣁ⾲㠃ࡢ㌿఩ኚ᥮ᣲືࢆᨺᑕග࡟

ຠᯝࡀᚓࡽࢀࠊኚ᥮ࡉࢀࡓ TED ࡀಖᣢࡉࢀࡿࡇ࡜ࡀ

ࡼࡿ X ⥺ࢺ࣏ࢢࣛࣇ࢕࣮ࢆ⏝࠸࡚ほᐹࡋࡓࠋSi ⵨Ẽ᫂ࡽ࠿࡟࡞ࡗࡓࠋ௒ᚋࡢᒎ㛤࡜ࡋ࡚ࠊSi ⵨Ẽᅽ࢚ࢵࢳᅽ࢚ࢵࢳࣥࢢࡉࢀࡓ SiC ࢙࢘ࣁ⾲㠃࡟࠾࠸࡚ BPD ඛࣥࢢฎ⌮᮲௳࡜ BPD ኚ᥮࡜ࡢ┦㛵ࠊኚ᥮ࡉࢀࡿ BPD➃㒊ศࡢ TED ࡬ࡢኚ᥮ࡢほᐹ࡟ᡂຌࡋࡓࠋࡲࡓ࢚ࣆ ࢱ࢟ࢩࣕࣝᡂ㛗ᚋࠊኚ᥮ࡉࢀࡓ TED ࡣ࢚ࣆࢱ࢟ࢩࣕ

Forum, 897, 375-378 (2017).

ࣝ⭷୰࡟⥔ᣢࡉࢀࠊBPD ࡢఏ᧛ࡣ☜ㄆࡉࢀ࡞࠿ࡗࡓࠋ

[8] 㡲⸨ᝆ௓, ⰱ⏣᫭Ⴙ, 㫽ぢ ⪽, ᆏཱྀ༟ஓ, 㔠Ꮚᛅᨺᑕග࡟ࡼࡿ X ⥺ࢺ࣏ࢢࣛࣇ࢕࣮ࡣࠊSi ⵨Ẽᅽ࢚ࢵ᫛, 㔝ୖ ᬡ, ໭␊ ┿, ඛ㐍ࣃ࣮༙࣡ᑟయศ⛉఍➨ 4ࢳࣥࢢࡉࢀࡓ SiC ⾲㠃࡟࠾ࡅࡿ㌿఩ኚ᥮ࡢᣲືࢆ㧗

ᅇㅮ₇఍ண✏㞟 IIA-26 (2017).

ศゎ⬟࠿ࡘ㠀◚ቯ࡛ホ౯ࢆྍ⬟࡜ࡍࡿ᭷ຠ࡞ᡭἲ࡛

[9] 㡲⸨ᝆ௓, ᆏཱྀ༟ஓ, ▮྿⣖ே, 㫽ぢ ⪽, 㔝ୖ ᬡ,࠶ࡿࡇ࡜ࡀ♧ࡉࢀࡓࠋ໭␊ ┿, 㔠Ꮚᛅ᫛, ඛ㐍ࣃ࣮༙࣡ᑟయศ⛉఍➨5ᅇㅮ₇఍ண✏㞟 IIB-13 (2018).

ㅰ㎡[10] ᅵ⏣⚽୍, ᙇ ᪕, ୰ᒣᾈ஧, ὸ㔝຾๎, ≉チᮏᐇ㦂ࡢ X ⥺ࢺ࣏ࢢࣛࣇ࢕࣮ホ౯࡟࠶ࡓࡾࠊከ኱࡞5958949ྕ

ࡈᣦᑟࢆ࠸ࡓࡔ࠸ࡓ▼ᆅ⪔ኴᮁ༤ኈ࡟ឤㅰࡢពࢆ⾲[11] N. A. Mahadik et al., “Mitigation of BPD byࡋࡲࡍࠋ

Pre-EpigrowthHigh

Temperature

SubstrateAnnealing”, Materials Science Forum, 858, 233-236ཧ⪃ᩥ⊩(2016).

[1] H. Lendenmann, et al., "Degradation in SiC
Bipolar Devices: Sources and Consequences ofElectrically Active Dislocations in SiC", Materials
Science Forum, 433-436, 901-906 (2003).
[2] S. Ha, et al., “Dislocation conversion in 4H
silicon carbide epitaxy”, J. Cryst. Growth 244 (3-4)
257-266 (2002).
[3] K. Konishi et al., “Stacking fault expansion frombasal plane dislocations converted into threadingedge dislocations in 4H-SiC epilayers under highcurrent stress”, J. Appl. Phys. 114, 014504 (2013).
[4] S. Hayashi et al., “Relationship between depthof basal-plane dislocations and expanded stacking
faults by application of forward current to 4H–SiC
p-i-n diodes”, Applied Physics Express 12, 051007(2019).
[5] ➉ᕝ኱㍜, ᮾ ๛, ᯇ⏣୍ᏹ, ᳃⏣㥴భ, 㛗⏣῟ோ,኱㇂ ᪼, 㔠Ꮚᛅ᫛, SiCཬࡧ㛵㐃࣡࢖ࢻࢠࣕࢵࣉ༙ᑟయ◊✲఍ ➨17ᅇㅮ₇఍ண✏㞟 P-12 (2008)㸬
[6] S. Ushio et al., "Surface Phase Diagram of4H-SiC {0001} Step-Terrace Structures during
Si-Vapor Etching in a TaC Crucible", Materials
Science Forum, 717-720, 573-576 (2012).
[7] S. Torimi et al., “Improving MechanicalStrength and Surface Uniformity to Prepare High
Quality Thinned 4H-SiC Epitaxial Wafer Using
Si-Vapor Etching Technology”, Materials Science