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Four Point Probe and Hall measurement

Adviser： Kuen-Hsien WuStudent：Wei-Ming Lin

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Outline

1. Introduction

2. Principle

3. Operation

4. Conclusions

5. References

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IntroductionFour-point probe measurement instrument mainly used for measuring the resistance of semiconductor thin films, that sheet resistance.

Sheet resistance is one of the important characteristics of a conductive material, particularly a conductive film.

Sheet resistance will be the film thickness、 grain size Inch and the impurity concentration and other factors.

Therefore, in the course of the process, often carefully monitor sheet resistance .

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Principle

V

I

S S S

d

W

sample

ρ ＝ V/I．W ． CF

Rs = V/I ． CF

As d/s＞ 20 → CF~4.54

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Operation

四點探針機台

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Operation

上機台輸入固定電流

下機台量測出電壓

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Operation

sample

橫桿下拉

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Operation

0.154767mV / 1 μ A × 4.54 =701Ω

Rs = 4.54 V/I

藍點要恆亮

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Conclusions

1 Sample size and shape does not affect the measurement results, therefore, the sample does not have to make special specifications .

2 Four-point probe measurements silicon wafer with a metal film sheet resistance the most common method.

3 Simple and fast, but more troublesome problem is to calculation results .

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Introduction

In 1978, Edwin H.Hall input current in the conductor applied magnetic field.

Conductor and the current direction the ends of the vertical , can measure the induced voltage .

Can determine the polarity and concentration of carriers , Known as the Hall effect .

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Principle

＋ －

Wεx

X

Z

y

Bz

Vxεy

＋

－VH

F ＝ qVxBz

q εy ＝ qVxBz

εy ＝ VxBz

VH ＝

εyW

正 P-type

負 n-type

ρ ＝ RH / μp

p-type

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Operation

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Operation

將 sample 固定在量測基板上

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Operation

將量測基板插入量測架上

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Operation

在量測座上放磁石並進行量測

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Operation

開啟量測軟體

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Operation

出現霍爾量測系統畫面

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Operation

輸入膜厚

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Operation

得到 data

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Hall measurements VS. Four-point probe

Hall measurements Four-point probe

Special specifications specimen Do not have to make special specifications

★ resistivity ★ mobility ★ carrier concentration

★ sheet resistance

★ sheet resistance × film thickness

＝ resistivity

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Conclusions

1Hall effect is mainly for detecting a semiconductor material,film samples can be measured resistivity, carrier concentration, carrier polarity, and mobility.

2Rapid measurement , Simple operation, simple to operate a computer, you can complete the measurement step , the film is detected with a great help.

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References

http://ezphysics.nchu.edu.tw/prophys/basicexp/expnote/hall/hall_97Feb.pdf物理實驗 - 霍爾效應

http://140.116.176.21/www/technique/SOP/SOP%204-Point%20Probe.pdf四點探針儀器介紹

http://mast-tech.com.tw/Resistivity%20Measurement.pdf 科豐國際有限公司

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Thank You