Patent ID: 6278132
Filing Date: 2001-08-21
Classification: H01L

Abstract:
A liquid crystal display device comprising:a substrate;an underlying film formed on said substrate;a shift register circuit comprising a plurality of clocked inverter circuits and a plurality of inverter circuits provided over said substrate, each of said clocked inverter circuits and said inverter circuits comprising at least one n-channel thin film transistor exhibiting normally OFF characteristics and at least one p-channel thin film transistor exhibiting normally OFF characteristics;said n-channel thin film transistor comprising a first crystalline semiconductor film comprising silicon having a thickness of 100 to 1,000 .ANG.;said p-channel thin film transistor comprising a second crystalline semiconductor film comprising silicon having a thickness of 100 to 1,000 .ANG.,wherein at least an edge portion of said first crystalline semiconductor film comprises boron introduced at a concentration of 1.times.10.sup.16 to 1.times.10.sup.19 /cm.sup.3, and at least a channel region of said second crystalline semiconductor film comprises boron introduced at a concentration of 1.times.10.sup.16 to 1.times.10.sup.19 /cm.sup.3, andwherein said shift register has an S value of 85 mV/dec or lower.