利用改进的电荷泵法研究SONOS存储器陷阱电荷的分布特性

在silicon-oxide-nitride-oxide-silicon(SONOS)等电荷俘获型不挥发存储器中,编程操作后注入电荷的分布会对器件的读取、擦写以及可靠性带来影响.利用电荷泵方法可以有效而准确地测量出注入电荷沿沟道方向的分布.为了提高测试精度,在进行电荷泵测试时,采用固定低电平与固定高电平相结合的方法,分别对SONOS器件源端和漏端进行注入电荷分布的测试.通过测试,最终获得SONOS存储器在沟道热电子注入编程后的电子分布.电子分布的峰值区域在漏端附近,分布宽度在50nm左右.

An Improved Charge Pumping Method to Study Distribution of Trapped Charges in SONOS Memory

In silicon-oxide-nitride-oxide-silicon (SONOS) memory and other charge trapping memories,the charge distribution after programming operation has great impact on the device's characteristics,such as reading,programming/erasing,and reliability.The lateral distribution of injected charges can be measured precisely using the charge pumping method.To improve the precision of the actual measurement,a combination of a constant low voltage method and a constant high voltage method is introduced during the charge pumping testing of the drain side and the source side,respectively.Finally,the electron distribution after channel hot electron programming in SONOS memory is obtained,which is close to the drain side with a width of about 50nm.