Channel-last replacement metal-gate vertical field effect transistor

A method of making a vertical transistor, the method comprising:

• forming a doped source on a substrate;
• depositing a sacrificial gate material on the source, the sacrificial gate material arranged between a first spacer disposed on the doped source and a second spacer disposed on the sacrificial gate material;
• forming a trench in the sacrificial gate material, the first spacer, and the second spacer to expose the doped source;
• growing an epitaxial layer within the trench to form a channel region extending from the doped source and through the sacrificial gate material;
• performing an epitaxial growth process to grow an epitaxial layer on a portion of the channel region to form a drain over the sacrificial gate material;
• depositing a dielectric material on the drain to form a spacer that protects the epitaxial growth;
• removing a portion of the sacrificial gate material and the second spacer that extends horizontally beyond the spacer arranged over the drain;
• removing remaining portions of the sacrificial gate material such that a portion of the second spacer remains beneath the spacer over the drain;
• and
• depositing a gate stack that surrounds the channel region between the doped source and the drain.