Bias-controlled deep trench substrate noise isolation integrated circuit device structures
View Patent ↗A novel and useful apparatus for and method of providing noise isolation between integrated circuit devices on a semiconductor chip. The invention addresses the problem of noise generated by digital switching devices in an integrated circuit chip that may couple through the silicon substrate into sensitive analog circuits (e.g., PLLs, transceivers, ADCs, etc.) causing a significant degradation in performance of the sensitive analog circuits. The invention utilizes a deep trench capacitor (DTCAP) device connected to ground to isolate victim circuits from aggressor noise sources on the same integrated circuit chip. The deep penetration of the capacitor creates a grounded shield deep in the substrate as compared with other prior art shielding techniques.
1. A method of noise isolation for use in an integrated circuit device, the method comprising the steps of:
providing a semiconductor substrate having a first portion in which aggressor devices are formed and a second portion in which victim devices are formed;
forming a deep trench capacitor between said first portion and said second portion; and
electrically connecting said deep trench capacitor to a ground node.
2. The method according to claim 1 , wherein said step of forming comprises providing a metal contact on said deep trench capacitor to minimize resistance of said connection to said ground node.
3. The method according to claim 1 , wherein said first portion and said second portion comprises one or more digital or analog circuits.