Three-dimensional memory device containing different pedestal width support pillar structures and method of making the same

US10269820B1 · kind B1 · utility

Assignee

• Sandisk Technologies, Inc. · US

Inventor

• Michimoto Kaminaga · Hitachinaka, JP

Key dates

• Filing date: Apr 3, 2018
• Grant date: Apr 23, 2019
• Expiry date: Apr 3, 2038

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10B43/50

Abstract

A three-dimensional memory device includes an alternating stack having stepped surfaces and including insulating layers and electrically conductive layers, memory stack structures extending through each layer of the alternating stack in a memory array region, and support pillar structures extending through the stepped surfaces of the alternating stack. The support pillar structures include first-type support pillar structures vertically extending through at least two electrically conductive layers and including a respective first dummy pedestal channel portion having a respective first maximum lateral dimension along a first horizontal direction, and second-type support pillar structures vertically extending through no more than a single electrically conductive layer, and including a respective second dummy pedestal channel portion having a respective second maximum lateral dimension along the first horizontal direction that is greater than the first maximum lateral dimension.