Lsi Manufacturing Process To Eliminate The Effects Of 1 / F Noise

With VLSI circuit advanced technology development, the integrated circuit devices are getting smaller. And in order to improve electrical parameters, The thickness of gate oxide which is the key layer of CMOS also has become thinner. But when IC technology go to 90 nm node, the most thin thickness of gate oxide met with the challenges. Because at that time the gate oxide thickness is already very thin(<20 A), the tunnel leakage current through mechanism has play a leading role. As the gate oxide layer thickness, further reduce leakage current will also to grid exponent form growth. In order to solve these problems, the new type gate oxide technology become to the new research direction.There are two ways to improve the dielectric coefficient of gate:one is to adopt the new materials, such as HfSiON etc. But adopt new materials involving grid material selection, the matching and lattice constant exposure etching and so on a series of crafts integration problems, so technology development cycle relatively long, not immediately meet the urgent needs of 90 nanotechnology. Another way is still keep the gate oxide, through the gate oxide film to be doping nitrogen in the density of nitrogen oxidation silicon to improve the dielectric coefficient.But the doping nitrogen gate oxide layer of CMOS will get bad 1/f noise adversely. This is because nitrogen in the gate oxide layer-the introduction of silicon interface released distorted silicon-oxygen bonds, reduced the interface stress, change the interface of the Si substrate near lattice structure, strengthened the carrier and decided by the lattice structure, the scattering of phonons and lowering the carriers are especially hole into the gate oxide layer potential barrier. So it is the main reason that CMOS get the bad noise characteristics.In this thesis, we analysis the integrated circuit gate oxide properties and interfacial characteristics for CMOS device 1/f noise Then we get the conclusion:the main method is to change the nitrogen's distribution. This is because all factors which affect CMOS device 1/ f noise are distributed in the gate oxide-silicon interface nearby. Just let nitrogen doped into the gate oxide, but far from the gate oxide silicon interface, can let the nitrogen gate oxide -to charged center and silicon interface lattice interface roughness produces little influence. Thus not to trigger 1/f noise's "switch". So it can prevent to get bad 1/f noise performace with doping nitrogen gate oxideIn this thesis, we introduces the method that doping nitrogen to gate oxide by plasma, and through design experiments to prove that plasma can made the nitrogen far from gate oxide-silicon interface, then obtain excellent interface CMOS device 1/f noise characteristics.