Method of forming a semiconductor device with memory cells, high voltage devices and logic devices on a substrate using a dummy area

US12144172B2 · kind B2 · utility

Assignee

• Silicon Storage Technology, Inc. · US

Inventors

• Zhuoqiang Jia · Mountain View, US
• Leo Xing · Shanghai, CN
• Xian Liu · Sunnyvale, US
• Serguei Jourba · Aix-en-Provence, FR
• Nhan Do · Saratoga, US

Key dates

• Filing date: May 16, 2022
• Grant date: Nov 12, 2024
• Expiry date: Aug 1, 2043

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D30/6892

Abstract

A method of forming a device on a semiconductor substrate having first, second, third and dummy areas, includes recessing the substrate upper surface in the first, second and dummy areas, forming a first conductive layer over the substrate, removing the first conductive layer from the third area and a second portion of the dummy area, forming a first insulation layer over the substrate, forming first trenches through the first insulation layer and into the substrate in the third area and the second portion of the dummy area, forming second trenches through the first insulation layer, the first conductive layer and into the substrate in the first and second areas and a first portion of the dummy area, and filling the first and second trenches with insulation material. Then, memory cells are formed in the first area, HV devices in the second area and logic devices in the third area.