1、1,2,XROM Layout,3,4,熱電子效應,5,6,7,8,9,10,11,12,13,14,15,16,17,Flash cells top view photo picture,18,SST cells cross section by Optical Microscope,19,20,SSTs flash cells TEM cross section photo picture,21,22,23,24,25,26,AMD Mirror Bit Flash Memory,27,AMD Mirror Bit Flash Memory(續),28,AMD Mirror Bit Fla
2、sh Memory(續),29,Mirror Bit Lay-out,30,31,32,33,34,35,36,37,38,39,40,41,42,43,HDROM的特色:專門針對高密度需求所發明的快閃記憶體,它的特色如下:每一個電晶體可以儲存三個位元每一個電晶體的面積比傳統快閃記憶晶胞小晶胞沒有過度抹除(over erase)的問題,並不利用多邏輯階方式來增加每一電晶體所 能儲存的位元數目HDROM缺點: 製程比堆疊式晶胞複雜 電路比較複雜HDROM發明背景由於未來快閃記憶晶胞往高密度發展是必然的趨勢,而且需求量也會越來越高,因此可以預測的到高密度快閃記憶晶胞將主宰整個快閃記憶體領域。傳統的
3、快閃記憶晶胞特色是平面方向結構,如堆疊型(stack gate) ,分裂控制閘型(split gate) ;常用在內崁式快閃記憶體的單一多晶矽型(single poly)或MNOS都是把電子打入浮動閘,藉以改變臨界電壓,44,45,HDROM剖面結構圖 (1)(X軸方向),p wafer,floating gate (poly1),control gate(poly 2),n+ as source,n+,p,n+,drain1,p,drain2,common control gate 1,common control gate 2,p,drain3,cell 1,cell 2,cell 3,common control gate3,n+,n+,common control gate 0,46,n+,p wafer,p,drain1,p,drain2,common control gate 4,p,drain3,cell 1,cell 2,cell 3,metal,metal,common control gate 5,HDROM剖面結構圖 (2) (Y軸方向),47,Bit line,控制閘,GND,GND,Word line,48,49,50,51,