An ionization chamber chip for a nano-aperture ion source, method of fabrication thereof, and a proton beam writing system

A nano-aperture ion source, the nano-aperture ion source comprising:

• an ionization chamber chip including
• a first substrate including a first depression formed in a back surface of the first substrate;
• a backing element attached at the back surface of the first substrate such that a chamber is formed including at least the first depression;
• a gas inlet formed in the first substrate in fluid communication with the chamber;
• and
• a first aperture structure formed in the first substrate in fluid communication with the chamber.

A method of fabricating an ionization chamber chip for a nano-aperture ion source, the method comprising:

• providing a first substrate including a first depression formed in a back surface of the first substrate;
• providing a backing element attached at the back surface of the first substrate such that a chamber is formed including at least the first depression;
• forming a gas inlet in the first substrate in fluid communication with the chamber;
• and
• forming a first aperture structure in the first substrate in fluid communication with the chamber.