Mai shi ne MOS Capacitor?

Maimaihuwa MOS Capacitor?

Makaranta MOS Capacitor

MOS na nufin Metal Oxide Semiconductor. An MOS capacitor yana da karkashin maida ko substrate, insulator, da kuma metal gate. A cikin yau daɗi, an yi gate daga n+ poly-silicon wanda ya fi koyar da metal. Silicon dioxide (SiO2) ta shirya a matsayin material dielectric tare da kafin kapasitor, inda metal da lamarin suna yi aiki a matsayin duwatsu biyu.

Kapasitar da ke MOS yana canza da voltaji da aka fada a terminali gate, a lokacin da body ana gudanar da ground.

Flat band voltage ita ce maimakon muhimmanci wajen MOS capacitor. Ana bayyana shi a matsayin voltaji da ba ake da zama a duwatsu kapasitor, saboda haka ba ake da electric field statik a matsayin oxide. Idan aka fada voltaji gate mai kyau da flat band voltage (Vgb > Vfb), akwai zama mai kyau a gate (poly silicon) da kuma zama mai hasu a semiconductor. Zama-zaman hasu ne suka iya samun electrons hasu da suke juye a siffofin surface. Wannan yana nufin surface accumulation.

Idan voltaji gate da aka fada ita ya kadan da flat band voltage (Vgb < Vfb), akwai zama hasu a matsayin interface tare da gate poly-silicon da oxide, da kuma zama mai kyau a semiconductor.

Wannan yana iya faru idan an kara electrons hasu daga siffofin surface, don haka an samun zama-zaman kyau daga donors. Wannan yana nufin surface depletion.

Idan MOS capacitor ba a yi amfani da shi baki daya, amma yana da muhimmanci a MOS transistors, wadannan su ne amfani da su daidai a cikin devices semiconductor.

Karakarata kapasitar-voltaji tare da MOS capacitor da body n-type yana ba da wannan,

Diagram Capacitance vs. Gate Voltage (CV) tare da MOS Capacitor. Flatband voltage (Vc-v curve of mos capacitorfb) yana haɓaka Accumulation region daga Depletion region. Threshold voltage (Vth) yana haɓaka depletion region daga inversion region.