Deep channel isolation structure and manufacturing method thereof

Abstract

The invention discloses a deep channel isolation structure and a manufacturing method thereof, and the manufacturing method comprises the steps: providing a semiconductor substrate, and sequentially forming an epitaxial layer, shallow channel isolation and nitride which are opposite to the semiconductor substrate in type on the semiconductor substrate; performing a photomask process of deep channel isolation and reactive ion etching on the shallow channel isolation; carrying out linear oxidation, and adopting TEOS deposition; carrying out TEOS etching to remove oxides at the top and the bottom; depositing polycrystalline silicon, carrying out a CMP (Chemical Mechanical Polishing) process and removing nitride; depositing an oxide and a nitride, and carrying out an LOCOS photomask process and reactive ion etching; carrying out LOCOS oxidation; removing nitride; and carrying out ILD deposition, wherein the Contact is connected with the semiconductor substrate through polycrystalline silicon. The oxide at the top and the oxide at the bottom are removed through the TEOS etching step, and a larger space is provided for filling of the polycrystalline silicon, so that the polycrystalline silicon is in direct contact with the semiconductor substrate, and the manufacturing process of a contact well is omitted.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to a deep trench isolation (Deep Trench Isolation, DTI) structure and a manufacturing method thereof. Background technique [0002] Traditional deep trench isolation structures such as figure 1 As shown, it needs to be combined with the deep P-well (Deep P-Well) to realize the contact of the P-type substrate (P-substrate). Specifically, the Contact is connected to the P-substrate through the Deep P-Well. Correspondingly, in the manufacturing process of the above-mentioned deep trench isolation structure, it is necessary to manufacture a P-type contact well, and a Deep P-Well photomask process is also required, and the manufacturing process is complicated. Contents of the invention [0003] The technical problem to be solved by the present invention is to provide a deep trench isolation structure and a manufacturing method thereof in order to overcome the defect in the prior art that...

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Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide a deep trench isolation structure and its manufacturing method in order to overcome the defect that the prior art needs to make a P-type contact well, which leads to a complicated manufacturing process.

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