Charged particle beam device and imaging method

1 . A charged particle beam device for irradiating a sample arranged in a sample chamber to be observed with a charged particle beam, the charged particle beam device comprising:

a plasma generation device to which a bias voltage is applicable to generate plasma containing charged particles for applying charges onto a side wall of a pattern of the sample;

a guide that guides the charged particles in the plasma generated by the plasma generation device to the pattern of the sample; and

a radio frequency power supply that applies a radio frequency bias voltage to the sample when the charged particles in the plasma are guided to the pattern of the sample.

2 . The charged particle beam device according to claim 1 , further comprising:

a detector that detects secondary electrons emitted from the sample by irradiating the sample with the charged particle beam; and

an estimation unit that estimates a shape of the pattern of the sample from a change in signal detected by the detector when the bias voltage applied to the plasma generation device is changed.

3 . The charged particle beam device according to claim 2 , further comprising a power supply control unit that changes a voltage applied to the plasma generation device with a predetermined time width and a predetermined voltage change width until a final voltage is reached.

4 . The charged particle beam device according to claim 1 , further comprising a switching unit that switches between the irradiation of the sample with the charged particle beam and the irradiation of the charged particles in the plasma generated by the plasma generation device at a predetermined timing.

5 . The charged particle beam device according to claim 1 , further comprising:

a database that stores a plurality of luminance changes of known patterns with respect to the bias voltage applied to the plasma generation device; and

an estimation unit that estimates a shape of an unknown pattern by collating a luminance change of the unknown pattern with respect to the bias voltage applied to the plasma generation device with the database.

6 . The charged particle beam device according to claim 1 , further comprising:

a database that stores a plurality of luminance changes of known patterns with respect to a charged amount obtained by analysis; and

an estimation unit that estimates a shape of an unknown pattern by collating a luminance change of the unknown pattern with respect to a charged amount obtained by actual measurement with the database.

7 . The charged particle beam device according to claim 1 , wherein the plasma generation device or the guide is provided in the sample chamber in an insulated state.

8 . An imaging method comprising:

applying a bias voltage to a plasma generation device that generates plasma such that plasma is generated by the plasma generation device;

emitting charged particles in the plasma generated by the plasma generation device to a sample via a guide to charge a side wall of a pattern of the sample; and

irradiating the charged sample with a charged particle beam to detect and image secondary electrons emitted from the sample; and

applying a radio frequency bias voltage to the sample using a radio frequency power supply when the charged particles in the plasma are guided to the pattern of the sample.

9 . The imaging method according to claim 8 , further comprising estimating a shape of the pattern of the sample from a change in signal detected when the bias voltage applied to plasma generation device is changed.

10 . The imaging method according to claim 8 , further comprising changing a voltage applied to the plasma generation device with a predetermined time width and a predetermined voltage change width until a final voltage is reached.

11 . The imaging method according to claim 8 , further comprising switching between the irradiation of the sample with the charged particle beam and the irradiation of the charged particles in the plasma generated by the plasma generation device at a predetermined timing.

12 . The imaging method according to claim 8 , further comprising:

storing a plurality of luminance changes of known patterns with respect to the bias voltage applied to the plasma generation device in a database; and

estimating a shape of an unknown pattern by collating a luminance change of the unknown pattern with respect to the bias voltage applied to the plasma generation device with the database.

13 . The imaging method according to claim 8 , further comprising:

storing a plurality of luminance changes of known patterns with respect to a charged amount obtained by analysis in a database; and

estimating a shape of an unknown pattern by collating a luminance change of the unknown pattern with respect to a charged amount obtained by actual measurement with the database.