Title :
Low-power and high-stability SRAM technology using a laser-recrystallized p-channel SOI MOSFET
Author :
Takao, Yoshihiro ; Shimada, Hiroshi ; Suzuki, Noriyuki ; Matsukawa, Yoshihiro ; Sasaki, Nobuo
Author_Institution :
Fujitsu Ltd., Kawasaki, Japan
fDate :
9/1/1992 12:00:00 AM
Abstract :
Laser recrystallization of p-channel SOI MOSFETs on an undulated insulating layer is demonstrated for SRAMs with low power and high stability. Self-aligned p-channel SOI MOSFETs for loads are stacked over bottom n-channel bulk MOSFETs for both drivers and transfer gates. A sufficient laser power assures the same leakage currents between SOI MOSFETs fabricated on an undulated insulating layer in memory cell regions and on an even insulating layer in field regions. The on/off ratio of the SOI MOSFETs is increased by a factor of 104, and the source-drain leakage current is decreased by a factor of 10-102 compared with those of polysilicon thin-film transistors (TFTs) fabricated by using low-temperature regrowth of amorphous silicon. A test 256-kb SRAM fabricated this technology shows improved stand-by power dissipation and cell stability. The process steps can be decreased to 83% of those TFT load SRAMs if both the peripheral circuit and memory cells are made with p-channel SOI and n-channel bulk MOSFETs
Keywords :
MOS integrated circuits; SRAM chips; VLSI; insulated gate field effect transistors; integrated circuit technology; laser beam annealing; recrystallisation annealing; 256 kbit; 3D SRAM cell; SRAM technology; Si-SiO2; cell stability; high stability; laser recrystallization; leakage currents; low power; n-channel bulk MOSFETs; on/off ratio; p-channel SOI MOSFETs; process steps reduction; self aligned MOSFETs; stand-by power dissipation; undulating insulating layer; Amorphous silicon; Circuit testing; Insulation; Laser stability; Leakage current; MOSFETs; Power lasers; Random access memory; Silicon on insulator technology; Thin film transistors;
Journal_Title :
Electron Devices, IEEE Transactions on
