Method for on-line monitoring of quality of ONO (Oxide-Nitride-Oxide) film in SONOS (Silicon Oxide Nitride Oxide Semiconductor) memory process

Abstract

The invention discloses a method for on-line monitoring of the quality of an ONO (Oxide-Nitride-Oxide) film in SONOS (Silicon Oxide Nitride Oxide Semiconductor) memory process. The method comprises: 1) grounding a body region, a source port and a drain port of an SONOS memory structure; 2) supplying forward current less than 1muA to a grid port of the SONOS memory structure and lasting for 20-30 seconds; 3) successively supplying a reverse current less than 1nA to the grid port, scanning the voltage of the grid port and drawing a voltage-time curve; 4) carrying out integration to calculate out the area surrounded by the drawn voltage-time curve and the lateral axis of a coordinate; 5) comparing the numerical value obtained in step 4) with a standard numerical value so as to judge the quality of the ONO film. With the method, a device can be tested once being produced and monitored in real time, so that the result can be fed back to the production line in time, and the influence on the production line due to delayed judgment can be avoided.

Description

technical field [0001] The invention relates to a method for monitoring the quality of an ONO film, in particular to an online method for monitoring the quality of an ONO film. Background technique [0002] SONOS structure, namely silicon, silicon oxide, silicon nitride, silicon oxide and polysilicon (bottom-up) five kinds of materials stacked composite gate structure. The SONOS structure is extremely compatible with standard CMOS technology, and has many advantages such as high durability, low power and radiation resistance. In addition, the SONOS architecture provides a more stable, easier-to-manufacture and cost-effective solution than other embedded non-volatile memory technologies. This technology is also widely used in the industry because of its compact structure and its ability to extend downwards. [0003] In the SONOS memory process, the preparation of ONO film is the core process. The quality of the ONO film directly determines the performance and reliability o...

AI Technical Summary

Problems solved by technology

Although the circuit-level test is relatively comprehensive, it needs to be carried out after all the processes are completed, and the quality of the ONO film cannot be judged in real time, which brings great risks to the production line.

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