J. Inst. Electrostat. Jpn.

, 30, 2 (2006) 83 88╬ଔ࿁〝ࡕ࠺࡞ߦࠃࠆࡃ࡝ࠬ࠲ߩࡁࠗ࠭ๆ෼․ᕈߩᡷༀદ ⮮ ᷕ*,1㧘㋈ ᧁ 㓷 ผ**㧘㋈ ᧁ ᥍ ᒾ*㧘ศ ᧛  ᣹**
㧔2005 ᐕ 7 ᦬ 8 ᣣฃઃ㧘2006 ᐕ 3 ᦬ 1 ᣣฃℂ㧕

Improvement of Noise Absorption Characteristics of Ceramic Varistor
Using Equivalent Circuit
Atsushi ITO*,1,Masafumi SUZUKI**, Haruhiko SUZUKI* and Noboru YOSHIMURA**(Received July 8, 2005; Accepted May 1, 2006)

Varistor has a lot of advantages compared with Zener diode, such as the symmetrical voltage-current
characteristic, the large capacitance and the high responsibility. Therefore, it is used as a protective element
against the static electricity and surge noise for mobile phones, video cameras, DVD-ROMs, DC motors and soon. Especially, SrTiO3 varistor is available for a noise absorption element, since it has a large capacitance and alarge non-linear coefficient between applied voltage and current at the region in a large current.
In this paper, we investigate the influence of the capacitance at the grain boundary and resistance in thecrystalline grain on the noise absorption characteristics of ceramic varistor using an equivalent circuit model.
The simulated results show that the noise occurred in a DC motor can be reduced with the increase of thecapacitance at the grain boundary near by the surface layer of the varistor and the decrease of the resistance inthe conduction layer of it.
1. ߪߓ߼ߦ߆ߒߥ߇ࠄ㧘ࡕ࡯࠲ߩ․ᕈ߇ᄌࠊߞߚ႐วߦߪᔅߕߒ߽

៤Ꮺ㔚⹤߿ࡆ࠺ࠝࠞࡔ࡜㧘 DVD-ROM㧘ฦ⒳ࡕ࡯࠲ߥ

චಽߥࡁࠗ࠭ๆ෼߇ⴕ߃ߥ޿႐ว߽޽ࠅ㧘૶↪ߔࠆࡕ࡯ߤ㧘ㄭᐕߩዊဳ㔚ሶᯏེߪ㧘ࠦࡦࡇࡘ࡯࠲ߦࠃࠆ೙ᓮ߇࠲ߩ․ᕈߦᔕߓߚࡃ࡝ࠬ࠲․ᕈߩᦨㆡൻ߇ᦸ߹ࠇߡ޿ࠆ㧚ⴕࠊࠇߡ޿ࠆ㧚ߎࠇࠄߩ㔚ሶᯏེౝߢ⊒↢ߔࠆࠨ࡯ࠫࡁ╩⠪ࠄߩ⎇ⓥࠣ࡞࡯ࡊߪ࠮࡜ࡒ࠶ࠢࡃ࡝ࠬ࠲ࠍ⚿᥏☸

ࠗ࠭߿㜞๟ᵄࡁࠗ࠭ߪ㧘ᯏེߩ⺋േ૞߿⎕უߦߟߥ߇ࠆ⇇ߣ⚿᥏☸ሶߦಽߌ㧘ࡃ࡝ࠬ࠲ߩ㔚᳇⊛․ᕈࠍḩ⿷ߔࠆᕟࠇ߇޽ࠆ㧚․ߦ⋥ᵹࡕ࡯࠲ߢߪࡉ࡜ࠪ㧙ᢛᵹሶ ߢࠗ╬ଔ࿁〝ࡕ࠺࡞ࠍឭ᩺ߒ㧘ࡁࠗ࠭ๆ෼․ᕈߩᦨㆡൻࠍ⋡ࡦ࠳ࠢ࠲ࡦࠬߩࠠ࠶ࠢࠝࡈ╬ߦߣ߽ߥ߁ࡁࠗ࠭ߩ⊒↢߇ᜰߒߡ߈ߚ 1-4)㧚߹ߚ㧘ߎߩ╬ଔ࿁〝ࡕ࠺࡞ࠍ↪޿ߡ㧘⋥໧㗴ߣߥߞߡ޿ࠆ㧚ߎࠇࠄߩࡁࠗ࠭ࠍ㒰෰ߔࠆߚ߼ߦࡃᵹࡕ࡯࠲ߦ߅޿ߡࠗࡦ࠳ࠢ࠲ࡦࠬߩࠠ࠶ࠢࠝࡈߦߣ߽ߥ࡝ࠬ࠲߇૶↪ߐࠇߡ޿ࠆ㧚ࡃ࡝ࠬ࠲ߩਛߢ߽․ߦ SrTiO3߁ࠨ࡯ࠫࡁࠗ࠭߇ࡃ࡝ࠬ࠲ౝㇱߢߤߩࠃ߁ߦๆ෼ߐࠇࠆ♽࠮࡜ࡒ࠶ࠢࡃ࡝ࠬ࠲ߪ㧘Ყセ⊛㔚࿶㧙㔚ᵹ․ᕈߩ㕖⋥ߩ߆ߦߟ޿ߡ߽ႎ๔ߒߡ޿ࠆ 4)㧚ߎߩ╬ଔ࿁〝ࡕ࠺࡞ࠍ✢ᕈ߇ᄢ߈ߊ㧘㕒㔚ኈ㊂߽ᄢ߈޿ߚ߼㧘ࠨ࡯ࠫๆ෼ߩߺ↪޿ࠆߎߣߦࠃࠅ㧘ࡃ࡝ࠬ࠲ߩࡁࠗ࠭ๆ෼ᯏ᭴ߩ⸃᣿߿㧘ߥࠄߕ㜞๟ᵄࡁࠗ࠭ߩๆ෼ߦ߽ఝࠇߚ․ᕈࠍ␜ߒ㧘⋥ᵹߘߩ㔚᳇⊛․ᕈߩᡷༀߦ߽೑↪ߔࠆߎߣ߇ߢ߈ࠆߚ߼㧘ࡕ࡯࠲╬ߩࡁࠗ࠭ኻ╷ߣߒߡ߽ᐢߊ↪޿ࠄࠇߡ޿ࠆ㧚ߒࡃ࡝ࠬ࠲ࠍ⸳⸘ߔࠆ਄ߢ᦭⋉ߥᜰᮡࠍਈ߃ࠆߎߣߣߥࠆ㧚ᧄ⎇ⓥߢߪ㧘వߦឭ᩺ߒߚ╬ଔ࿁〝ࡕ࠺࡞ߩ߁ߜ㧘⚿ࠠ࡯ࡢ࡯࠼㧦࠮࡜ࡒ࠶ࠢࡃ࡝ࠬ࠲㧘࿁〝ࠪࡒࡘ࡟࡯࠲㧘⺃㔚․ᕈ㧘ࡁࠗ࠭ๆ෼․ᕈ
* ⑔ፉᎿᬺ㜞╬ኾ㐷ቇᩞ㔚᳇Ꮏቇ⑼㧔970-8034
޿ࠊ߈Ꮢᐔ਄⨹Ꮉሼ㐳የ 30㧕
Fukushima National College of Technology,
30 Nagao Kamiarakawa Taira, Iwaki , 970-8034, Japan**⑺↰ᄢቇᎿቇ⾗Ḯቇㇱ㔚᳇㔚ሶᎿቇ⑼㧔010-8502⑺↰Ꮢᚻᒻቇ࿦↸ 1-1㧕Engineering and Resource Science, Akita University,
1-1 Tegata Gakuenmachi, Akita 010-8502, Japan1
atsuito@fukushima-nct.ac.jp᥏☸⇇ߩ㕒㔚ኈ㊂ߣ⚿᥏☸ሶߩᛶ᛫ߦᵈ⋡ߒ㧘ߎࠇࠄߩ୯߇⋥ᵹࡑࠗࠢࡠࡕ࡯࠲ߢ⊒↢ߔࠆࠨ࡯ࠫࡁࠗ࠭ߩๆ෼․ᕈߦ෸߷ߔᓇ㗀ߦߟ޿ߡ㧘Pspice ࠍ↪޿ߚࠪࡒࡘ࡟࡯
࡚ࠪࡦߦࠃࠅᬌ⸛ߒߚ㧚߹ߚ㧘ࡃ࡝ࠬ࠲ౝㇱߩߤߩㇱಽߩ㕒㔚ኈ㊂ߣᛶ᛫߇ࡁࠗ࠭ๆ෼․ᕈߦᓇ㗀ࠍ෸߷ߔߩ߆ߦߟ޿ߡߩ⸃ᨆ߽ⴕ޿㧘ߤߩࠃ߁ߥ․ᕈߩࡃ࡝ࠬ࠲߇ࠃ
ࠅലᨐ⊛ߦࡁࠗ࠭ࠍๆ෼ߔࠆߩ߆ߦߟ޿ߡ߽ᬌ⸛ߒߚ㧚1

84 (26)30

2. ࡁࠗ࠭ๆ෼․ᕈ

22006⊒↢ߔࠆࡁࠗ࠭ߦ෸߷ߔ㕒㔚ኈ㊂ߣᛶ᛫ߩᓇ㗀ࠍᬌ⸛ᧄ⎇ⓥߢߪ㧘⴫㕙ౣ㉄ൻဳ SrTiO3 ࡃ࡝ࠬ࠲ࠍ⚿᥏☸⇇ߔࠆߚ߼㧘ోߡߩጀߩ⚿᥏☸⇇ߩ㕒㔚ኈ㊂ߣ⚿᥏☸ሶߩߩ㕒㔚ኈ㊂ߣ⚿᥏☸ሶߩᛶ᛫ߦࠃࠅ╬ଔ࿁〝ࡕ࠺࡞ߢ⴫

ᛶ᛫ࠍ⴫㧝ߦ␜ߒߚ୯ߩ 1/5㨪5 ୚ߣߒ㧘⊒↢ߔࠆࡁࠗ࠭ߒ㧘ࡁࠗ࠭ๆ෼․ᕈߦߟ޿ߡᬌ⸛ߔࠆ㧚╬ଔ࿁〝ߦߟ޿ᵄᒻࠍ࿁〝ࠪࡒࡘ࡟࡯࠲ߢ᳞߼ߚ㧚⚿᥏☸⇇ߩ㕒㔚ኈ㊂4)ߡߩ⹦⚦ߪᣢߦႎ๔ߒߡ޿ࠆࠃ߁ߦ 㧘࿑ 1 ߩࠃ߁ߦ᳿

ࠍᄌൻߐߖߚ႐วߩࡁࠗ࠭ᵄᒻࠍ࿑ 3 ߦ㧘⚿᥏☸ሶߩᛶቯߒߚ㧚╬ଔ࿁〝ਛߩฦᛶ᛫୯߅ࠃ߮㕒㔚ኈ㊂ߪ⴫ 1 ߦ᛫ࠍᄌൻߐߖߚ႐วߩࡁࠗ࠭ᵄᒻࠍ࿑ 4 ߦ␜ߔ㧚޿ߕࠇ␜ߔ㧚ߥ߅㧘ฦጀߩᛶ᛫ߣ㕒㔚ኈ㊂ߪ a ጀࠍ଀ߣߔࠆߣ㧘ߩ႐วߦ߅޿ߡ߽ࡁࠗ࠭ߪࠬࠗ࠶࠴ࠍ off ߦߒߚ⍍㑆ߦหߓጀౝߩᛶ᛫ߣ㕒㔚ኈ㊂ߪోߡหߓ୯ߣߒߚ㧚↢ߓߡ޿ߚߚ߼㧘ࠬࠗ࠶࠴ off ߩㇱಽࠍ᜛ᄢߒߡ␜ߒߚ㧚ࡃ࡝ࠬ࠲ߩࡁࠗ࠭ๆ෼․ᕈߪ⋥ᵹࡑࠗࠢࡠࡕ࡯࠲ࠍࡃ࡝ࠬ࠲ߩ╬ଔ࿁〝ᮨᡆߒߚ╬ଔ࿁〝ߦ߅޿ߡᬌ⸛ߔࠆ㧚࿑ 2 ߦ␜ߔࠃ߁ߦ
ࡑࠗࠢࡠࡕ࡯࠲ࠍ╬ଔ࿁〝ߢ⴫ߒ㧘ߎࠇߦ࿑ 1 ߩࡃ࡝ࠬ࠲ߩ╬ଔ࿁〝ࠍਗ೉ߦធ⛯ߔࠆ㧚ࡑࠗࠢࡠࡕ࡯࠲ߢ⊒↢ߔࠆࡁࠗ࠭ߪ㧘ࡉ࡜ࠪߣᢛᵹሶ ߩធ⸅ߩ㓙ߦ↢ߕࠆߚ߼㧘ߎࠇࠍࠬࠗ࠶࠴ߩ on㧘off ߢᮨᡆߒߚ㧚ࠦࠗ࡞ߩࠗ

1mH40ǡ

ࡦ࠳ࠢ࠲ࡦࠬߪ 1mH㧘Ꮞ✢ᛶ᛫ߪ 40ǡ㧘㔚Ḯ㔚࿶ߪ 10Vߣߒ㧘ࠬࠗ࠶࠴ࠍ 0.5ms 㑆㓒ߢ on-off ߒߚ㧚ࡑࠗࠢࡠࡕ࡯࠲ㇱabRaaጀ

CaCaCbbጀ

Rb10VCb࿑ 2 ࠪࡒࡘ࡟࡯࡚ࠪࡦ࿁〝Fig.2 Simulated circuit.

Rccጀdጀ

Cc

Cd

Cc

Rd
Cd

㪈㪇eጀ
fጀ

Ce

CfCe㔚࿶㩷㪲㪭㪴Re
Rf
CfRggጀ
Cg

Chhጀ

CgRh

㪇
㪇㪅㪐㪐

Ch

Riiጀ
jጀ

Ci

Cj

CiRcon㪌㪈㪅㪇㪋㪈㪅㪇㪐㪄㪌

Rj㪚㪑㪌୚㪚㪑㪉୚㪚㪑㪈୚㪚㪑㪈㪆㪉㪚㪑㪈㪆㪌Cj㪄㪈㪇ዉ૕ጀCcon㪄㪈㪌࿑ 1 ࡃ࡝ࠬ࠲ߩ╬ଔ࿁〝ࡕ࠺࡞Fig.1 Equivalent circuit of ceramic varistor.

࿑ 3 ోߡߩጀߩ㕒㔚ኈ㊂ C ߇ᄌൻߒߚߣ߈ߩࡁࠗ࠭ᵄᒻ
Fig.3 Calculated noise waveform when the capacitance C
at all layer were changed.

⴫ 1 ╬ଔ࿁〝ߩࡄ࡜ࡔ࡯࠲
Table 1. Parameter of equivalent circuit.

㪈㪇㔚࿶㩷㪲㪭㪴⚿᥏☸ౝ⚿ ᥏ ☸ ⇇ᛶ᛫ R [ǡ]㕒㔚ኈ㊂ C [nF]

aጀ

10.0

10.0

bጀ

0.05

1000.0c,e,g,i ጀ

3.32

1.0

d,f,h ጀ

0.043

200.0

jጀ

0.043

100.0

ዉ૕ጀ

13.28

5.0

ᛶ᛫[ǡ]

㪌
㪇
㪇㪅㪐㪐

㔚࿶ଐሽဳ
นᄌᛶ᛫

㪈㪅㪈㪋
ᤨ㑆㩷㪲㫄㫊㪴㪄㪌4)

㪄㪈㪇
㪄㪈㪌

㪈㪅㪇㪋

㪈㪅㪇㪐

㪈㪅㪈㪋
ᤨ㑆㩷㪲㫄㫊㪴
㪩㪑㪌୚
㪩㪑㪉୚
㪩㪑㪈୚
㪩㪑㪈㪆㪉
㪩㪑㪈㪆㪌
㪩㪑㪈㪆㪈㪇

࿑ 4 ోߡߩጀߩᛶ᛫ R ߇ᄌൻߒߚߣ߈ߩࡁࠗ࠭ᵄᒻ
Fig.4 Calculated noise waveform when the resistance R
at all layer were changed.

85 (27)࿑ 3 ߦ␜ߔࠃ߁ߦ⊒↢ߔࠆࡁࠗ࠭ᵄᒻߦߪ⚿᥏☸⇇ߩࠢ୯ߪ㕒㔚ኈ㊂ߩჇടߦᓥ޿ᷫዋߒ㧘ࡇ࡯ࠢ୯߹ߢߩᤨ㑆߇㐳ߊߥࠆ௑ะߦ޽ࠆ㧚߹ߚ㧘ࡁࠗ࠭߇෼᧤ߔࠆ߹ߢߩᤨ㑆߇㐳ߊߥࠆߎߣ߇ࠊ߆ࠆ㧚⚿᥏☸ሶߩᛶ᛫ࠍᄌൻߐߖߚ႐วߦߪ㧘ᛶ᛫ߩჇടߦࠃࠅ㧘ࡁࠗ࠭ᵄᒻߩࡇ࡯ࠢ୯ߪჇടߒߚ㧚ࡁࠗ࠭߇෼᧤ߔࠆ߹ߢߩᤨ㑆ߦߪᄢ߈㪎㪇㪇วᚑ䉟䊮䊏䊷䉻䊮䉴 㪲㱅㪴㕒㔚ኈ㊂ߩᓇ㗀߇ᄢ߈ߊ⃻ࠇߚ㧚⊒↢ߔࠆࡁࠗ࠭ߩࡇ࡯㪌㪇㪇㪋㪇㪇㪊㪇㪇㪉㪇㪇㪈㪇㪇ߥᄌൻߪ⷗ࠄࠇߥ޿㧚ోߡߩጀߩ㕒㔚ኈ㊂㧯ߣᛶ᛫㧾ࠍ㪇㪈㪅㪇㪜㪂㪇㪋ᄌൻߐߖߚ႐วߩࡁࠗ࠭ߩࡇ࡯ࠢ୯ߩᄌൻࠍ࿑ 5 ߦ␜ߔ㧚ห࿑߆ࠄ߽㕒㔚ኈ㊂߇ᄢ߈ߊ㧘߹ߚ㧘ᛶ᛫߇ዊߐߊߥࠆࡁࠗ࠭ߦ෸߷ߔᓇ㗀߇ᄢ߈޿ߎߣ߇ࠊ߆ࠆ㧚⚿᥏☸⇇ߩ㕒㔚ኈ㊂ߣ⚿᥏☸ሶߩᛶ᛫߇ᄌൻߒߚ႐วC ߣᛶ᛫ R ࠍᄌൻߐߖߚߣ߈ߩวᚑࠗࡦࡇ࡯࠳ࡦࠬߩ๟
ᵄᢙଐሽᕈࠍߘࠇߙࠇ␜ߔ㧚ోߡߩጀߩ㕒㔚ኈ㊂ C ߇ᷫዋߔࠆߎߣߦࠃࠅ㧘100kHz ࠃࠅૐ޿๟ᵄᢙߦ߅ߌࠆวᚑࠗࡦࡇ࡯࠳ࡦࠬ߇Ⴧടߒߡ޿ࠆ㧚߹ߚ㧘ోߡߩጀߩᛶ᛫
R ߇Ⴧടߒߚ႐วߦ߽วᚑࠗࡦࡇ࡯࠳ࡦࠬߪჇടߒߡ޿

㪈㪅㪇㪜㪂㪇㪍㪊㪇㪇วᚑ䉟䊮䊏䊷䉻䊮䉴 㪲㱅㪴ߐߩ๟ᵄᢙଐሽᕈࠍ᳞߼ߚ㧚࿑ 6 ߅ࠃ߮࿑ 7 ߦ㕒㔚ኈ㊂๟ᵄᢙ 㪲㪟㫑㪴วᚑࠗࡦࡇ࡯࠳ࡦࠬ
Fig.6 Calculated impedance of varistor
when the capacitance C at all layer were changed.

ࠊ߆ࠆ㧚߹ߚ㧘ᛶ᛫ࠃࠅ㕒㔚ኈ㊂ߩᄌൻߩᣇ߇⊒↢ߔࠆߣᛶ᛫ R ࠍᄌൻߐߖߚ႐วߩวᚑࠗࡦࡇ࡯࠳ࡦࠬߩᄢ߈㪈㪅㪇㪜㪂㪇㪌࿑ 6 ోߡߩጀߩ㕒㔚ኈ㊂㧯߇ᄌൻߒߚߣ߈ߩߎߣߦࠃࠅ⊒↢ߔࠆࡁࠗ࠭ߩࡇ࡯ࠢ୯߇ᷫዋߔࠆߎߣ߇ߩࡃ࡝ࠬ࠲ߩ㔚᳇⊛․ᕈߣߒߡ㧘ోߡߩጀߩ㕒㔚ኈ㊂ C㪚㪑㪈㪇୚㪚㪑㪌୚㪚㪑㪉୚㪚㪑㪈୚㪚㪑㪈㪆㪉㪚㪑㪈㪆㪌㪚㪑㪈㪆㪈㪇㪍㪇㪇㪩㪑㪈㪇୚㪩㪑㪌୚㪩㪑㪉୚㪩㪑㪈୚㪩㪑㪈㪆㪉㪩㪑㪈㪆㪌㪩㪑㪈㪆㪈㪇㪉㪌㪇㪉㪇㪇㪈㪌㪇㪈㪇㪇㪌㪇㪇㪈㪅㪇㪜㪂㪇㪋㪈㪅㪇㪜㪂㪇㪌๟ᵄᢙ 㪲㪟㫑㪴

㪈㪅㪇㪜㪂㪇㪍ࠆ㧚㕒㔚ኈ㊂߇ᷫዋߒߚ႐ว߅ࠃ߮ᛶ᛫߇Ⴧടߒߚ႐วߣ߽ߦ㧘ࡁࠗ࠭ߩࡇ࡯ࠢ୯߇Ⴧടߔࠆߎߣߪ㧘วᚑࠗࡦ࿑ 7 ోߡߩጀߩᛶ᛫㧾߇ᄌൻߒߚߣ߈ߩ

ࡇ࡯࠳ࡦࠬߩჇടߣ㑐ㅪ߇⷗ࠄࠇࠆ㧚ࡁࠗ࠭ߩ๟ᵄᢙߪ

วᚑࠗࡦࡇ࡯࠳ࡦࠬ
Fig.7 Calculated impedance of the varistor
when the resistance R at all layer were changed.

ᢙ 10kHz㨪ᢙ 100kHz ߣ⠨߃ࠄࠇ㧘⚿᥏☸ሶౝߩᛶ᛫ࠍᄌൻߐߖࠆ႐วࠃࠅ☸⇇ߩ㕒㔚ኈ㊂ࠍᄌൻߐߖߚ႐วߩᣇ߇ߎߩ๟ᵄᢙᏪၞߢߩวᚑࠗࡦࡇ࡯࠳ࡦࠬߩᄌൻ߇ᄢ
߈ߊ㧘ߎߩߚ߼㧘ࡁࠗ࠭ᵄᒻߦ෸߷ߔᓇ㗀߽ᄢ߈ߊ⃻ࠇ

3. ࡁࠗ࠭ๆ෼․ᕈߩ⸃ᨆ
ᣢߦႎ๔ߒߡ޿ࠆࠃ߁ߦ 4㧕㧘ࡃ࡝ࠬ࠲ౝㇱߩ㔚ᵹߪᄙߊ߇⴫㕙߆ࠄౝㇱߦะ߆޿㧘ዉ૕ጀࠍㅢࠅ㧘ౣ߮⴫㕙߳ࠆߣ⠨߃ࠄࠇࠆ㧚߽ߤࠆߣ޿߁⚻〝ࠍߚߤࠆ㧚࿑ 8 ߦฦጀࠍᵹࠇࠆ㔚ᵹᵄᒻࠍ␜ߔ㧚ోጀ䈱㕒㔚ኈ㊂㪚䈍䉋䈶ᛶ᛫㪩䈱୚₸㩷㩷㩷㩷䌛୚䌝㪇㪅㪈ߒ߆ߒ㧘ࡃ࡝ࠬ࠲ౝㇱߦ߅޿ߡ㧘ฦጀߩ㕒㔚ኈ㊂߿ᛶ㪈㪈㪇䊉䉟䉵䈱䊏䊷䉪୯㩷㪲㪭㪴㪇᛫߇ࡁࠗ࠭ๆ෼․ᕈߦߤߩࠃ߁ߥᓇ㗀ߒߡ޿ࠆߩ߆ߪ᣿ࠄ߆ߢߪߥ޿㧚ߎߩߚ߼㧘ฦጀߩ㕒㔚ኈ㊂ߣᛶ᛫߇ࡁࠗ࠭ᵄᒻߦ෸߷ߔᓇ㗀ߦߟ޿ߡᬌ⸛ߔࠆߚ߼㧘1 ጀߛߌߩ㪄㪌㕒㔚ኈ㊂ߣᛶ᛫ࠍ 1/5㨪5 ୚⒟ᐲߩ▸࿐ߢᄌൻߐߖ㧘⊒↢ߔࠆࡁࠗ࠭ࠍ᳞߼ߚ㧚㪄㪈㪇㪚㪄㪈㪌㪩․ቯߩጀߩ⚿᥏☸⇇ߩ㕒㔚ኈ㊂ࠍᄌൻߐߖߚ႐วߦࡃ
࡝ࠬ࠲ߩ╬ଔ࿁〝ࡕ࠺࡞ߩਔ┵ߢ⊒↢ߔࠆࡁࠗ࠭ᵄᒻࠍ
࿑ 9㨪12 ߦ㧘߹ߚ㧘⊒↢ߔࠆࡁࠗ࠭ߩࡇ࡯ࠢ୯ࠍ࿑ 13࿑ 5 ోߡߩጀߩ㕒㔚ኈ㊂㧯߅ࠃ߮ᛶ᛫㧾߇ߦ␜ߔ㧚⴫㕙ጀߩ㕒㔚ኈ㊂ Ca ߩᄌൻߦࠃࠆࡁࠗ࠭ߩᵄᒻ

ᄌൻߒߚߣ߈ߩࡁࠗ࠭ߩࡇ࡯ࠢ୯
Fig.5 Peak of noise waveform when the capacitance C andthe resistance R at all layer were changed.

ߩᄌൻߪ࿑ 9 ߦ␜ߔࠃ߁ߦ޽߹ࠅᄢ߈ߊߥߊ㧘10 ୚⒟ᐲ

ߦᄢ߈ߊᄌൻߐߖࠆߣࡁࠗ࠭߇ᷫዋߔࠆ㧚ᰴߦ⴫㕙ߦု⋥ߥᣇะߩ㕒㔚ኈ㊂ Cb ࠍᄌൻߐߖߚ႐วߦߪ㧘ࡁࠗ࠭ᵄ

86 (28)30

2ᒻ߇ᄢ߈ߊᄌൻߒ㧘Cb ߩᓇ㗀߇ᄢ߈޿ߎߣ߇ࠊ߆ࠆ㧚Cbⴕߞߚᤨ㑆ౝߢߪࡁࠗ࠭ߩᝄേߪ෼᧤ߒߥ߆ߞߚ㧚࿑ 11㪌㔚࿶ 㪲㪭㪴

߇ᄢ߈ߊߥࠆߣࡁࠗ࠭ߩࡇ࡯ࠢ୯ߪᷫዋߔࠆ߇㧘⸃ᨆࠍ

2006

㪇

ߪ㕒㔚ኈ㊂ Cc ࠍᄌൻߐߖߚ႐วࠍ␜ߒߡ޿ࠆ㧚࿑ߩࠃ߁㪈㪈㪅㪇㪌ߦ㧘㕒㔚ኈ㊂ߩᄌൻߦࠃࠆࡁࠗ࠭ᵄᒻߩᄌൻߪ߶ߣࠎߤ
⷗ࠄࠇߥ߆ߞߚ㧚࿑ 13 ߦ␜ߔࠃ߁ߦ㧘ࠃࠅౝㇱߩ⴫㕙ߦ㪄㪌㪚㪸㪑㪈㪇୚㪚㪸㪑㪌୚㪚㪸㪑㪉୚㪚㪸㪑㪈୚㪚㪸㪑㪈㪆㪉㪚㪸㪑㪈㪆㪌ᐔⴕߥᣇะߩ㕒㔚ኈ㊂ Ce㧘Cg㧘Ci ߦߟ޿ߡ߽ Cc ߣห᭽ߩ௑ะ߇޽ࠅ㧘ࡃ࡝ࠬ࠲ߩౝㇱߦⴕߊߦᓥߞߡ⊒↢ߔࠆ㪄㪈㪇ࡁࠗ࠭ߦ෸߷ߔ㕒㔚ኈ㊂ߩᓇ㗀ߪዊߐߊߥࠆ⚿ᨐ߇ᓧࠄ࿑ 9 Ca ߇ᄌൻߒߚߣ߈ߩࡁࠗ࠭ᵄᒻ
Fig.9 Calculated noise waveform.
(Ca changed)ࠇߚ㧚࿑ 12 ߦ㕒㔚ኈ㊂ Cd ࠍᄌൻߐߖߚ႐วࠍ␜ߔ㧚࿑ߩࠃ߁ߦ㧘 Cd ߩᄌൻߦࠃࠅࡁࠗ࠭ᵄᒻߪᄌൻߒ㧘㕒㔚ኈ㊂ߩჇടߦᓥ޿⊒↢ߔࠆࡁࠗ࠭ߪᷫዋߔࠆ௑ะߦ޽ࠆ㧚޿ߡ߽ Cd ߣห᭽ߩ௑ะ߇޽ࠅ࿑ 13 ߦ␜ߔࠃ߁ߦ㧘ౝㇱߦⴕߊߦᓥߞߡ⊒↢ߔࠆࡁࠗ࠭ߦ෸߷ߔ㕒㔚ኈ㊂ߩᓇ㗀ߪዊߐߊߥࠆߣ޿߁⚿ᨐ߇ᓧࠄࠇߚ㧚ዉ૕ጀߩ㕒㔚ኈ㊂㪌
㔚࿶㩷㪲㪭㪴

ࠃࠅౝㇱߩ⴫㕙ߦု⋥ߥᣇะߩ㕒㔚ኈ㊂ Cf㧘Ch㧘Cj ߦߟ㪈㪅㪈ᤨ㑆㩷㪲㫄㫊㪴

㪇㪈㪈㪅㪇㪌ᤨ㑆㩷㪲㫄㫊㪴㪈㪅㪈㪄㪌㪚㪹㪑㪌୚

Ccon ࠍᄌൻߐߖߚ႐วߦߪ㧘Cc ࠍᄌൻߐߖߚ႐วߣ߶߷ห᭽ߩ௑ะࠍ␜ߒ⊒↢ߔࠆࡁࠗ࠭ߦ෸߷ߔᓇ㗀ߪዊߐ߆㪚㪹㪑㪉୚

㪄㪈㪇

㪚㪹㪑㪈୚
㪚㪹㪑㪈㪆㪉

ߞߚ㧚એ਄ߩߎߣ߆ࠄ⴫㕙ߦㄭ޿ጀߩ⚿᥏☸⇇ߩ㕒㔚ኈ
㊂㧘․ߦ⴫㕙ߦု⋥ߥᣇะߩ㕒㔚ኈ㊂ߪ⊒↢ߔࠆࡁࠗ࠭

㪚㪹㪑㪈㪆㪌

㪄㪈㪌

࿑ 10 Cb ߇ᄌൻߒߚߣ߈ߩࡁࠗ࠭ᵄᒻ
Fig.10 Calculated noise waveform.
(Cb changed).

ߦ෸߷ߔᓇ㗀߇ᄢ߈ߊ㧘㕒㔚ኈ㊂ߩჇടߦᓥ޿㧘ࡁࠗ࠭ߩࡇ࡯ࠢ୯ߪᷫዋߔࠆߣ޿߁⚿ᨐ߇ᓧࠄࠇߚ㧚࿑ 14 ߅ࠃ߮࿑ 15 ߦ␜ߔ㧚࿑ 14 ߪ⴫㕙ጀߩᛶ᛫ࠍᄌൻߐ
ߖߚ႐วߩࡁࠗ࠭ᵄᒻࠍ␜ߒߡ޿ࠆ㧚ᛶ᛫ߩᓇ㗀ߪᄢ߈ߊߪ⃻ࠇߡ޿ߥ޿߇㧘ᛶ᛫ߩჇടߦࠃࠅࡁࠗ࠭ߩࡇ࡯ࠢ㪌㔚࿶ 㪲㪭㪴ᰴߦ⚿᥏☸ሶߩᛶ᛫ࠍᄌൻߐߖߚ႐วߩࡁࠗ࠭ᵄᒻࠍ㪇㪈㪈㪅㪇㪌୯ߪࠊߕ߆ߦჇടߒߚ㧚ߎࠇߪዉ૕ጀࠍ㒰ߊోߡߩጀߩᛶ᛫ߦߟ޿ߡ߽߶߷ห᭽ߩ⚿ᨐ߇ᓧࠄࠇߚ㧚࿑ 15 ߦዉ૕㪈㪅㪈ᤨ㑆㩷㪲㫄㫊㪴㪚㪺㪑㪌୚㪄㪌㪚㪺㪑㪉୚ጀߩᛶ᛫ Rcon ࠍᄌൻߐߖߚ႐วߩࡁࠗ࠭ᵄᒻࠍ␜ߔ㧚㪚㪺㪑㪈୚㪚㪺㪑㪈㪆㪉㪄㪈㪇㪚㪺㪑㪈㪆㪌

࿑ 11 Cc ߇ᄌൻߒߚߣ߈ߩࡁࠗ࠭ᵄᒻ
Fig.11 Calculated noise waveform.
(Cc changed) .

㪇
㪄㪇㪅㪇㪌

㪈

㪈㪅㪇㪈

㪈㪅㪇㪉

㪈㪅㪇㪊㪈㪅㪇㪋㪈㪅㪇㪌ᤨ㑆 㪲㫄㫊㪼㪺㪴㪄㪇㪅㪈㪠㪸㪠㪹
㪠㪺
㪠㪻
㪠㪼
㪠㪽
㪠㪾
㪠㪿㪠㫀
㪠㫁

㪄㪇㪅㪈㪌
㪄㪇㪅㪉
㪄㪇㪅㪉㪌
㪄㪇㪅㪊

࿑ 8 ฦጀߩ㔚ᵹᵄᒻ
Fig.8 Calculated current in the each layer.

㪌㔚࿶㩷㪲㪭㪴

㔚ᵹ䇭㪲㪘㪴

㪇㪅㪇㪌

㪇
㪈

㪈㪅㪇㪌

㪈㪅㪈
ᤨ㑆 㪲㫄㫊㪴

㪄㪌

㪚㪻㪑㪌୚
㪚㪻㪑㪉୚
㪚㪻㪑㪈୚
㪚㪻㪑㪈㪆㪉

㪄㪈㪇㪚㪻㪑㪈㪆㪌

࿑ 12 Cd ߇ᄌൻߒߚߣ߈ߩࡁࠗ࠭ᵄᒻ
Fig.12 Calculated noise waveform.
(Cd changed)87 (29)㪚㪺㫆㫅㪚㫁㪚㫀㪚㪿㪚㪾㪚㪽㪚㪼㪚㪻㪚㪺㪚㪹㪚㪸㪇㪄㪍㪈㪈㪅㪇㪌㪄㪏㪄㪈㪇㪄㪈㪉㪄㪈㪋㪄㪈㪍㪈㪅㪈ᤨ㑆 㪲㫄㫊㪴

㪈㪇୚㪌୚㪉୚㪈୚㪈㪆㪉㪈㪆㪌㪈㪆㪈㪇࿑ 13 ฦጀߩ㕒㔚ኈ㊂߇ᄌൻߒߚߣ߈ߩࡁࠗ࠭ߩࡇ࡯ࠢ୯
Fig.13 Peak of calculated noise waveform when the capacitanceat the each layer was changed.

ࡁࠗ࠭ߩࡇ࡯ࠢ୯ߪዉ૕ጀߩᛶ᛫߇ᷫዋߔࠆߦᓥ޿ᷫዋߒߡ޿ࠆ㧚ᛶ᛫ߦ㑐ߒߡߪ⚿᥏☸ሶߩᛶ᛫ߪᧄ⎇ⓥߢⴕ

㪄㪌

㪩㪸㪑㪌୚
㪩㪸㪑㪉୚
㪩㪸㪑㪈୚
㪩㪸㪑㪈㪆㪉

㪄㪈㪇㪩㪸㪑㪈㪆㪌

࿑ 14 Ra ߇ᄌൻߒߚߣ߈ߩࡁࠗ࠭ᵄᒻ
Fig.14 Calculated noise waveform.
(Ra changed)㪌㔚࿶㩷㪲㪭㪴

䊉䉟䉵䈱䊏䊷䉪୯㩷㪲㪭㪴㪄㪋㔚࿶ 㪲㪭㪴㪌

ᄌൻ䈘䈞䈢㕒㔚ኈ㊂㪇㪈ߞߚ▸࿐ߢߪࡁࠗ࠭ๆ෼ߦᄢ߈ߥᓇ㗀ߪਈ߃ߕ㧘ዉ૕ጀ㪈㪅㪇㪌ᤨ㑆㩷㪲㫄㫊㪴⸃ᨆߦ↪޿ߚ࠮࡜ࡒ࠶ࠢࡃ࡝ࠬ࠲ߪ⴫㕙ౣ㉄ൻဳߩ࡝㪩㪺㫆㫅㪑㪌୚㪩㪺㫆㫅㪑㪉୚㪩㪺㫆㫅㪑㪈୚㪩㪺㫆㫅㪑㪈㪆㪉ࡦࠣࡃ࡝ࠬ࠲ߢ޽ࠆߚ߼㧘ᾲಣℂ᷷ᐲ߿ᾲಣℂᤨ㑆ߥߤ㪩㪺㫆㫅㪑㪈㪆㪌㪩㪺㫆㫅㪑㪈㪆㪈㪇ߩᛶ᛫߇ࡁࠗ࠭ๆ෼ߦᓇ㗀ࠍ෸߷ߔߎߣ߇␜ߐࠇߚ㧚ߢฦጀߩ☸⇇ߩ㕒㔚ኈ㊂߿⚿᥏☸ሶߩᛶ᛫ࠍ೙ᓮߔࠆ੐㪄㪌㪈㪅㪈㪄㪈㪇߇ߢ߈㧘߹ߚ㧘㔚ᭂ㑆㓒ߩᄌᦝߢ᳓ᐔᣇะߩ㕒㔚ኈ㊂߿ᛶ᛫ࠍ೙ᓮߔࠆ੐߇ߢ߈ࠆ㧚ߘߎߢ㧘ฦጀߩ㕒㔚ኈ㊂ߣᛶ᛫߇⊒↢ߔࠆࡁࠗ࠭ߩᷫዋߦ෸߷ߔᓇ㗀ࠍߐࠄߦ⹦ߒ࿑ 15 Rcon ߇ᄌൻߒߚߣ߈ߩࡁࠗ࠭ᵄᒻ
Fig.15 Calculated noise waveform.
(Rcon changed)ߊ⺞ߴࠆߚ߼ߦᰴߩࠃ߁ߥ⸃ᨆࠍⴕߞߚ㧚ᆎ߼ߦ a ጀߩ㕒㔚ኈ㊂ߩߺࠍ 2 ୚ߦჇട㧘ᰴߦ a ጀߣ b ጀࠍ 2 ୚ߦჇട㧘a ጀ㨪c ጀࠍ 2 ୚ߦჇടߣ޿߁ࠃ߁ߦ㧘ฦጀߩ㕒㔚ኈ⴫㕙߆ࠄౝㇱߦะ߆ߞߡ㕒㔚ኈ㊂ߩ୚₸ࠍ 1/5㨪5 ୚㊂ࠍ⴫㕙߆ࠄౝㇱߦะ߆ߞߡᲑ㓏⊛ߦჇടߐߖߚ㧚߹ߚ㧘ߦᲑ㓏⊛ߦᄌ߃㧘ߎߩߣ߈⊒↢ߔࠆࡁࠗ࠭ߩࡇ࡯ࠢ୯ࠍ

ᛶ᛫ߩ႐วߦߪ㧘ᆎ߼ a ጀߩᛶ᛫ߩߺࠍ 1/10 ߦᷫዋ㧘ᰴ

࿑ 18 ߦ␜ߔ㧚࿑߆ࠄ㕒㔚ኈ㊂ Cb ߇ᄌൻߒߚߣ߈ߦࡁࠗ

ߦ a ጀߣ b ጀࠍ 1/10 ߦᷫዋߣ޿߁ࠃ߁ߦ㧘ฦጀߩᛶ᛫ࠍ

࠭ߩࡇ࡯ࠢ୯߇ᄢ߈ߊᄌൻߔࠆߚ߼㧘Cb ߩᓇ㗀߇ᄢ߈޿⴫㕙߆ࠄౝㇱߦะ߆ߞߡᲑ㓏⊛ߦᷫዋߐߖߚ㧚ߎߣ߇ࠊ߆ࠆ㧚㕒㔚ኈ㊂ࠍჇടߐߖࠆ႐วߦߪ㧘㕒㔚ኈ

࿑ 16 ߦ⚿᥏☸⇇ߩ㕒㔚ኈ㊂ߩ୯ࠍ⴫㕙߆ࠄౝㇱߦะ㊂ Cd ࠃࠅౝㇱߩኈ㊂߇Ⴧടߔࠆߣ㧘ࡁࠗ࠭ߩࡇ࡯ࠢ୯ߪ߆ߞߡᲑ㓏⊛ߦჇടߐߖߡⴕߊ႐วߦࡃ࡝ࠬ࠲ਔ┵ߦ⊒Ⴧടߩ௑ะߦ޽ࠆ㧚ߎߩ௑ะߪ㕒㔚ኈ㊂ࠍ 5 ୚ߦߒߚߣ

↢ߔࠆࡁࠗ࠭ᵄᒻࠍ␜ߔ㧚⴫㕙ߦㄭ޿㕒㔚ኈ㊂ Cd ߹ߢߪ߈ߦᄢ߈ߊߥߞߚ㧚৻ᣇ㧘㕒㔚ኈ㊂ࠍᷫዋߐߖࠆ႐วߦ

㕒㔚ኈ㊂ߩჇടߦࠃߞߡ⊒↢ߔࠆࡁࠗ࠭ߪᷫዋߒߚ㧚ߒߪ㧘⴫㕙ߦㄭ޿ጀߩ㕒㔚ኈ㊂ߩᷫዋߦࠃࠅ㧘ࡁࠗ࠭ߩࡇ߆ߒ㧘ߎࠇࠃࠅౝㇱߩ㕒㔚ኈ㊂ࠍჇടߐߖࠆߣ㧘ࡁࠗ࠭࡯ࠢ୯ߪჇടߒߚ㧚߹ߚ㧘㕒㔚ኈ㊂ Cd ࠃࠅౝㇱߩኈ㊂߇ߪࠊߕ߆ߢߪ޽ࠆ߇Ⴧടߩ௑ะࠍ␜ߒߚ㧚ᷫዋߔࠆߣࡁࠗ࠭ߩࡇ࡯ࠢ୯ߪ⧯ᐓᷫዋߒߡ޿ࠆ㧚⚿᥏☸ሶߩᛶ᛫ࠍࡃ࡝ࠬ࠲⴫㕙߆ࠄౝㇱߦะ߆ߞߡᲑ

࿑ 16 ߅ࠃ߮࿑ 18 ߩ⚿ᨐ߆ࠄ㧘⊒↢ߔࠆࡁࠗ࠭ߩࡇ࡯㓏⊛ߦᷫዋߐߖߚ႐วߦ⊒↢ߔࠆࡁࠗ࠭ᵄᒻࠍ࿑ 17 ߦࠢ୯ࠍᷫዋߐߖࠆߚ߼ߦߪ㧘⴫㕙ߦㄭ޿ጀߩ㕒㔚ኈ㊂ࠍ␜ߔ㧚࿑ߩࠃ߁ߦ⴫㕙߆ࠄౝㇱߦะ߆޿ᛶ᛫ࠍᲑ㓏⊛ߦᄢ߈ߊߒ㧘ࡃ࡝ࠬ࠲ౝㇱߩዉ૕ጀߦㄭ޿ጀߩ㕒㔚ኈ㊂ߪᷫዋߐߖࠆߣ㧘ᛶ᛫ߩᷫዋߦࠃࠅᰴ╙ߦࡁࠗ࠭ߩࡇ࡯ࠢዊߐߊߔࠆߎߣ߇ലᨐ⊛ߢ޽ࠆߣ޿߁⚿ᨐ߇ᓧࠄࠇߚ㧚୯ߪᷫዋߒߚ㧚߹ߚ㧘ዉ૕ጀߩᛶ᛫ߩᷫዋߦࠃࠆࡁࠗ࠭
ᵄᒻߩࡇ࡯ࠢ୯ߩᷫዋ߇ᄢ߈޿ߎߣ߇ࠊ߆ࠆ㧚88 (30)30㪈㪈㪅㪇㪌㔚࿶㩷㪲㪭㪴

㪄㪉

2

2006

4. ߹ߣ߼
ᧄ⎇ⓥߦ߅޿ߡߪ㧘⴫㕙ౣ㉄ൻဳ SrTiO3 ♽࠮࡜ࡒ࠶ࠢᤨ㑆 㪲㫄㫊㪴

ࡃ࡝ࠬ࠲ࠍౝㇱߩᓸ⚦᭴ㅧࠍ⠨ᘦߒߚ㔚᳇⊛ߥ╬ଔ࿁〝ߦ⟎߈឵߃㧘⚿᥏☸⇇ߩ㕒㔚ኈ㊂ߣ⚿᥏☸ሶߩᛶ᛫߇ࡁ㪄㪋㫆㫉㫀㪾㫀㫅㪸㫃
㪚㪸㩽㪚㪹㪑㪉୚㪚㪸䌾㪚㪻㪑㪉୚㪚㪸䌾㪚㪽㪑㪉୚㪚㪸䌾㪚㪿㪑㪉୚㪚㪸䌾㪚㫁㪑㪉୚㪚㪸䌾㪚㪺㫆㫅㪑㪉୚㪄㪍ࠗ࠭ๆ෼․ᕈߦ෸߷ߔᓇ㗀ߦߟ޿ߡ⸃ᨆߒߚ㧚ᓧࠄࠇߚ߅߽ߥ⚿ᨐࠍએਅߦ␜ߔ㧚(1)ࡕ࡯࠲ߢ⊒↢ߔࠆࡁࠗ࠭ߪ⚿᥏☸⇇ߩ㕒㔚ኈ㊂ߩჇടߦࠃࠅᷫዋߒߚ㧚㪄㪏(2)ᧄ⎇ⓥߢⴕߞߚ▸࿐ౝߢߪ⚿᥏☸ሶߩᛶ᛫ߪࡁࠗ࠭
ๆ෼․ᕈߦ෸߷ߔᓇ㗀ߪዊߐ߆ߞߚ㧚࿑ 16 㕒㔚ኈ㊂ࠍᲑ㓏⊛ߦჇടߐߖߚߣ߈ߩࡁࠗ࠭ᵄᒻ
Fig.16 Calculated noise waveform when the capacitance of theeach layer were increased step by step from the surface
layer toward the conduction layer.
㪈㪈㪅㪇㪌ߦࠃࠅ㧘⊒↢ߔࠆࡁࠗ࠭ߩࡇ࡯ࠢ୯ߪᷫዋߒߚ㧚(4)ࡃ࡝ࠬ࠲ౝㇱߩዉ૕ጀߦㄭ޿ጀߩ⚿᥏☸⇇ߩ㕒㔚ኈ
㊂߇ᷫዋߔࠆߎߣߦࠃࠅ㧘⊒↢ߔࠆࡁࠗ࠭ߩࡇ࡯ࠢ୯ߪ⧯ᐓᷫዋߒߚ㧚㪄㪉㔚࿶ 㪲㪭㪴(3)⴫㕙ߦㄭ޿ጀߩ⚿᥏☸⇇ߩ㕒㔚ኈ㊂߇Ⴧടߔࠆߎߣ

ᤨ㑆㩷㪲㫄㫊㪴

(5)ዉ૕ጀߩᛶ᛫߇ᷫዋߔࠆߎߣߦࠃࠅ㧘⊒↢ߔࠆࡁࠗ࠭
ߪᷫዋߒߚ㧚㪄㪋એ਄ߩ╬ଔ࿁〝ࡕ࠺࡞ࠍ↪޿ߚࠪࡒࡘ࡟࡯࡚ࠪࡦߩ⚿㫆㫉㫀㪾㫀㫅㪸㫃㪩㪸㩽㪩㪹㪑㪈㪆㪈㪇㪩㪸䌾㪩㪻㪑㪈㪆㪈㪇㪩㪸䌾㪩㪽㪑㪈㪆㪈㪇㪩㪸䌾㪩㪿㪑㪈㪆㪈㪇㪩㪸䌾㪩㫁㪑㪈㪆㪈㪇㪩㪸䌾㪩㪺㫆㫅㪑㪈㪆㪈㪇㪄㪍㪄㪏ᨐ߆ࠄ㧘࠮࡜ࡒ࠶ࠢࡃ࡝ࠬ࠲ߩࡁࠗ࠭ๆ෼․ᕈߪࡃ࡝ࠬ
࠲ߩ⴫㕙ߦㄭ޿ጀߩ⚿᥏☸⇇ߩ㕒㔚ኈ㊂ࠍᄢ߈ߊ㧘ዉ૕ጀߦㄭ޿ጀߩ㕒㔚ኈ㊂ߪዊߐߊ㧘߹ߚ㧘ዉ૕ጀߩᛶ᛫ࠍ
ዊߐߊߔࠆߎߣߢᡷༀ߇࿑ࠇࠆߎߣ߇᣿ࠄ߆ߣߥߞߚ㧚࿑ 17 ᛶ᛫ࠍᲑ㓏⊛ߦᷫዋߐߖߚߣ߈ߩࡁࠗ࠭ᵄᒻ
Fig.17 Calculated noise waveform when the resistance of the eachlayer were decreased step by step from the surface layer
toward the conduction layer..

߹ߚ㧘એ਄ߩ⚿ᨐߪ㧘࠮࡜ࡒ࠶ࠢࡃ࡝ࠬ࠲ߩ⴫㕙ㄭߊߣౝㇱߩ㕒㔚ኈ㊂߇ᷝട‛ߩടᷫ߿὾ᚑ᷷ᐲ㧘὾ᚑᤨ㑆㧘὾ᚑ㔓࿐᳇ߥߤߢ޽ࠆ⒟ᐲ೙ᓮน⢻ߢ޽ࠆߎߣ߆ࠄ㧘ࠃࠅലᨐ⊛ߦࡁࠗ࠭ࠍๆ෼ߔࠆߚ߼ߩ࠮࡜ࡒ࠶ࠢࡃ࡝ࠬ࠲ߩ⸳⸘ߦᓎ┙ߚߖࠆߎߣ߇น⢻ߢ޽ࠆߣ⠨߃ࠄࠇࠆ㧚ᣣ㗃ࠃࠅߏഥജ㗂޿ߚዊ═ේᱜ᳁ࠍᆎ߼ߣߔࠆ TDK㫆㫅㪚㪸䌾㪚㪺㪚㪸䌾㪚㫁㪚㪸䌾㪚㫀㪚㪸䌾㪚㪿㪚㪸䌾㪚㪽㪚㪸䌾㪚㪾㪚㪸䌾㪚㪼㪚㪸䌾㪚㪻㪚㪸䌾㪚㪺㪚㪸䌾㪚㪹㪚㪸㫆㫉㫀㪾㫀㫅㪸㫃㕒㔚ኈ㊂䉕ᄌൻ䈘䈞䈢ጀෳ⠨ᢥ₂䊉䉟䉵䈱䊏䊷䉪୯ 㪲㪭㪴㪇1) ㋈ᧁ㓷ผ,ᩊ↰ାᖝ,ศ᧛᣹㧦㔚ቇ,115-A,(1995)384
2) ㋈ᧁ㓷ผ,ᩊ↰ାᖝ,ศ᧛᣹㧦㔚ቇ,116-A,(1996)177
3) ㋈ᧁ㓷ผ,ᩊ↰ାᖝ,ศ᧛᣹㧦㕒㔚᳇ቇળ⹹, 24(2000)343
4) ㋈ᧁ㓷ผ,ᩊ↰ାᖝ,ศ᧛᣹㧦㕒㔚᳇ቇળ⹹, 25(2001)153

㪄㪌㪄㪈㪇

㪄㪈㪌

㧔ᩣ㧕SA ੐ᬺㇱߩ㑐ଥฦ૏ߦᗵ⻢↳ߒ਄ߍ߹ߔ㧚

㪌୚
㪉୚
㪈㪆㪉
㪈㪆㪌

࿑ 18 㕒㔚ኈ㊂߇ᄌൻߒߚߣ߈ߩࡁࠗ࠭ᵄᒻߩࡇ࡯ࠢ୯
Fig.18 Peak of noise waveform when the capacitance of the eachlayer were changed step by step from the surface layer
toward the conduction layer.