JPS63148636A - Terminating point detector for ion milling equipment - Google Patents

Abstract

PURPOSE:To facilitate detecting the terminating point of treatment of a sample without fail even if the sample is optically transparent by a method wherein an ion beam collector is provided on the rear of a rotary sample holder and an ion beam transmitted through the sample is captured and utilized as a terminating point detection signal. CONSTITUTION:A rotary sample holder 4 is provided in a vacuum chamber 1 which is evacuated by an evacuation unit 3 and a sample 5 and an ion beam collector 6 are fixed to the front surface and the back surface of the holder 4 respectively. An ion beam is applied to the sample 5 and the sample 5 is milled by the ion beam and gradually made to be thinner with the progress of milling. If a pin hole is drilled in the sample 5, the transmitted ion beam 9 enters the ion beam collector 6. The transmitted ion beam 9 captured by the ion beam collector 6 is detected by a terminating point detecting circuit 7 as an ion beam current and a signal is transmitted to a main part control circuit 8 to terminate the operation of the main part. With this constitution, the terminating point can be detected without fail even if the sample is optically transparent.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ion milling apparatus, and particularly to an end point detector for ion milling suitable for detecting the end point of an optically transparent sample.

[Conventional technology]

With conventional end point detectors that use laser light, it is extremely difficult to detect the end point in optically transparent samples because the difference in transmittance of the laser light is small.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not take into account the end point detection of an optically transparent sample, and has a practical problem with a transparent sample.

An object of the present invention is to reliably detect the end point even in an optically transparent sample.

[Means for solving problems]

The above object is achieved by installing an ion beam collector on the back of the rotating sample holder to collect the ion beam that has passed through the sample and using it as an end point detection signal.

[Effect]

The ion beam emitted from the ion gun mills and thins the sample set on the rotating sample stage. As the milling progresses and a pinhole is opened in the sample, the ion beam passes through the sample, and the ions on the back of the rotating sample holder. It will now reach the beam collector. By extracting this as an ion beam current and detecting the end point, it is possible to reliably detect the end point even in an optically transparent sample without using laser light.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

A rotating sample holder 4 is installed in a vacuum chamber 1 that is evacuated by an exhaust unit 3.

A sample 5 is fixed on the top surface, and an ion beam collector 6 is fixed on the back surface. The sample 5 is irradiated by the ion gun 2. It is milled by an ion beam and gradually becomes thinner. Milling progresses and sample 5
When the pinhole is opened, the transmitted ion beam 9 enters the ion beam collector 6.

The transmitted ion beam 9 incident on the ion beam collector 6 is detected as an ion beam current by the end point detection circuit 7, and a signal is sent to the main body control circuit 8 to stop the operation of the main body 1.

According to this embodiment, the end point can be reliably detected even in an optically transparent sample.

〔Effect of the invention〕

According to the present invention, the end point can be reliably detected even with an optically transparent sample, thereby preventing excessive milling of the sample and detecting the end point regardless of the sample, which is effective in unmanned operation of the ion milling apparatus.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention.

Claims (1)

[Claims] 1. In an ion milling device consisting of a vacuum chamber, an ion gun installed in the vacuum chamber, and a rotating sample holder installed on the optical axis of the ion beam, an ion beam collector for collecting ion beam current is installed on the back of the rotating sample holder. An end point detector for an ion milling device, characterized by being provided with.