The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 17, 1996
Filed:
May. 22, 1995
Umesh Sharma, Austin, TX (US);
Kuo-Tung Chang, Austin, TX (US);
Motorola Inc., Schaumburg, IL (US);
Abstract
A method for fabricating a 1-transistor EEPROM device, which can be programmed and erased by Fowler-Nordheim tunneling includes the formation of a memory gate (28) overlying a tunneling region (22), and aligning source (32) and drain (34) regions in a semiconductor substrate (10), such that a vertically oriented electric field (46) is created in the tunneling region (22). The memory gate (28) is coupled to a contact region (30) by a connecting portion (31). A select gate (14) controls a portion of the channel region in the substrate (10) adjacent to the tunneling region (22). The EEPROM device is programmed by applying a voltage of a first polarity memory gate (28), while applying a voltage of a second polarity to the source region (32), the drain region (34), and to the substrate (10). Under the applied voltages, charge carriers tunnel through a tunnel oxide layer (40) and into a silicon nitride layer (42), located intermediate to the memory gate (28) and the tunnel region (22). To erase the EEPROM device, the polarity of the applied voltages is reversed, and charge carriers of an opposite conductivity type tunnel into the silicon nitride layer (42).