Etching method for magnetic tunnel junction

A method for etching magnetic tunnel junction, using an etching apparatus including a sample loading chamber, a vacuum transition chamber, a reactive ion plasma etching chamber, an ion beam etching chamber, a coating chamber, and a vacuum transmission chamber, wherein, a wafer is treated and processed in the reactive ion plasma etching chamber, the ion beam etching chamber, and the coating chamber in accordance with specific sequences and conditions without interrupting a vacuum, the method comprising:

• a sample preparation step of forming on a semiconductor substrate a structure to be etched including a magnetic tunnel junction;
• a sample loading step of loading the sample into the sample loading chamber and passing the sample through the vacuum transition chamber to the vacuum transmission chamber;
• a reactive ion etching step of bringing the sample into the reactive ion plasma etching chamber and etching the sample to a bottom electrode with reactive ion plasma, and then returning the sample to the vacuum transmission chamber;
• an ion beam cleaning step of bringing the sample into the ion beam etching chamber to remove metallic residues and perform sample surface treatment with an ion beam, to completely remove a sidewall metal contamination and a sidewall damage layer formed in the reactive ion etching step, and metal residues above the bottom electrode of the device and above a dielectric layer between bottom electrodes of different devices, and then returning the sample to the vacuum transmission chamber;
• a protection step of bringing the sample into the coating chamber to perform coating protection on the upper surface and periphery of the sample after etching, and then returning the sample to the vacuum transmission chamber;
• and
• a sample taking step of returning the sample from the vacuum transmission chamber through the vacuum transition chamber to the sample loading chamber;
• wherein in the ion beam cleaning step, a sidewall of the magnetic tunnel junction is removed by a thickness of 0.1 nm to 10.0 nm.