Super-junction device and manufacturing method thereof
AssigneeSilicon-Magic Semiconductor Technology (Hangzhou) Co., Ltd.
InventorJiakun Wang
Life of this patent
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Abstract
The present disclosure relates to a super-junction device and a manufacturing method thereof. In the manufacturing method, a first plurality of semiconductor pillars are formed in an epitaxial layer and a sacrificial stack is formed above the epitaxial layer. The sacrificial stack is used as a hard mask both for a body region and for a source region, and has a sidewall which controls a channel length of the super-junction device to reduce process fluctuation in different batches and improve reliability of the super-junction device.
Claims20
A method for manufacturing a super-junction device, comprising:
- forming an epitaxial layer above a semiconductor substrate;
- forming a first plurality of semiconductor pillars in the epitaxial layer;
- forming a sacrificial stack above the epitaxial layer;
- forming a body region in the epitaxial layer with the sacrificial stack as a first hard mask, the body region having a first edge aligned with the first hard mask and a second edge aligned with a first photoresist which is in direct contact with an upper surface of the epitaxial layer;
- forming a sidewall on a side surface of the sacrificial stack;
- forming a source region in the body region with the sacrificial stack and the sidewall as a second hard mask, the source region having a first edge aligned with the second hard mask;
- removing the sacrificial stack;
- and
- forming a gate stack on the epitaxial layer,
- wherein the gate stack extends across the first edge of the body region and the first edge of the source region such that a channel length of the super-junction device corresponds to a sidewall thickness of the sacrificial stack,
- wherein the first photoresist is completely removed before removing the sacrificial stack.
A method for manufacturing a super-junction device, comprising:
- forming an epitaxial layer above a semiconductor substrate;
- forming a first plurality of semiconductor pillars in the epitaxial layer;
- forming a sacrificial stack above the epitaxial layer;
- forming a body region in the epitaxial layer with the sacrificial stack as a first hard mask, the body region having a first edge aligned with the first hard mask;
- forming a sidewall on a side surface of the sacrificial stack;
- forming a source region in the body region with the sacrificial stack and the sidewall as a second hard mask, the source region having a first edge aligned with the second hard mask;
- removing the sacrificial stack;
- and
- forming a gate stack on the epitaxial layer,
- wherein the gate stack extends across the first edge of the body region and the first edge of the source region such that a channel length of the super-junction device corresponds to a sidewall thickness of the sacrificial stack,
- wherein at least one of the first plurality of semiconductor pillars extends to a depth level below a bottom surface of the body region.
Dependencies are inferred from the claim text.