发明名称 |
SCANNING TUNNELING POTENTIO-SPECTROSCOPIC MICROSCOPE AND A DATA DETECTING METHOD |
摘要 |
A bias voltage UB including a sine-wave voltage UTsin omega ot and an off-set voltage UREG is applied to an electrode (14) on a sample (10). A potential U1 of the electrode (14) is represented by: U1 = UREG + UTsin omega ot. A voltage including the bias voltage UB and a voltage DELTA U is applied to an electrode (16) on the sample (10). A probe (12) is approached to the sample (10) by several nm, and a tunnel current IT flows therebetween. And the probe (12) scans the surface of the sample. During the scan, the position of the probe (12) is servo-controlled in the z-direction, to make constant the average absolute value of the tunnel current. The servo voltage is recorded thereby obtaining an STM image. Given that the potential difference between the electrode (14) and a surface portion facing the probe (12) is US(x), the average of U1 + US(x) becomes zero when the average of the tunnel current IT is zero. Accordingly, <US(x) + UREG + TTsin omega ot> = 0, that is, US(x) = - UREG. Thus, by recording - UREG the potential distribution US(x) on the sample surface is determined. Spectroscopic data is obtained by an analog operation unit (32), on the basis of a differential conductance DIFFERENTIAL IT/ DIFFERENTIAL UT calculated from the tunnel current signal IT and the bias voltage UT.
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申请公布号 |
US5185572(A) |
申请公布日期 |
1993.02.09 |
申请号 |
US19900585880 |
申请日期 |
1990.09.20 |
申请人 |
OLYMPUS OPTICAL CO., LTD. |
发明人 |
YAGI, AKIRA;OKADA, TAKAO;MORITA, SEIZO;MIKOSHIBA, NOBUO |
分类号 |
G01Q60/12;G01B7/34;G01Q30/04;G01Q60/14 |
主分类号 |
G01Q60/12 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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