公开(公告)号：US20180158648A1

公开(公告)日：2018-06-07

申请号：US15570803

申请日：2015-05-01

Applicant: HITACHI HIGH-TECHNOLOGIES CORPORATION

Inventor： Masazumi TONE ,  Hiroshi TOUDA ,  Fujio ONISHI

IPC: H01J37/24 ,  H01J37/244 ,  H01J37/22 ,  H01J37/08 ,  H01J37/248 ,  H01J37/26

CPC classification number: H01J37/241 ,  H01J37/08 ,  H01J37/18 ,  H01J37/222 ,  H01J37/244 ,  H01J37/248 ,  H01J37/26 ,  H01J37/28 ,  H01J2237/2448

Abstract: In a charged particle apparatus with an ion pump, which is a charged particle beam apparatus with an ion pump including a charged particle beam irradiation detecting unit for irradiating a sample with a charged particle beam in a chamber and detecting a secondary charged particle, an image processing unit for forming a secondary charged particle image from a detection signal of the detected secondary charged particle, an output unit for processing at the image processing unit and outputting an image, an ion pump for maintaining the interior of the processing chamber in a vacuum state, a driving power supply unit of the ion pump, and a high voltage cable for connecting the ion pump and the driving power supply unit, the driving power supply unit of the ion pump is structured to include a high voltage power supply circuit unit for operating the ion pump, a load current detection circuit unit for detecting a load current applied to the ion pump, and a canceller circuit unit for reducing low frequency noise applied to the load current detection circuit unit in order to sufficiently reduce low frequency noise of the power supply of the ion and to measure the degree of vacuum with a high accuracy.

公开(公告)号：US20180066986A1

公开(公告)日：2018-03-08

申请号：US15561190

申请日：2016-03-16

Applicant: HITACHI HIGH-TECHNOLOGIES CORPORATION

Inventor： Yutaka KASAI ,  Fujio ONISHI ,  Osamu TASAKI ,  Hidetsugu TANOUE ,  Kazuhiro TANAKA

IPC: G01J1/44 ,  G01N21/66 ,  G01N23/225 ,  G01T1/164 ,  G01T1/20 ,  G01N21/956

CPC classification number: G01J1/44 ,  G01J1/42 ,  G01J2001/444 ,  G01N21/66 ,  G01N21/956 ,  G01N23/203 ,  G01N23/22 ,  G01N23/225 ,  G01T1/1647 ,  G01T1/20 ,  G01T1/208 ,  H01J37/28

Abstract: A signal detected by a photomultiplier tube is pre-amplified and converted into a digital signal. A time average value of signal components, each of which has a voltage lower than a predetermined base threshold value, is calculated as a base voltage. A signal that has been subjected to base correction processing is subjected to threshold value processing and to base correction processing in a non-incident state in which light is not incident on the photomultiplier tube. An output signal thereof is subjected to dark current calculation processing; and a light emission signal amount is calculated by subtracting, from the signal component of the detection light obtained by the threshold value processing, a time average value of the signal components of the dark current. As the result, discriminating the dark current pulse from floor noises enhances the accuracy of the base voltage, and thus the accuracy of light detection.