Method for forming ultra-shallow junctions using laser annealing

The method for forming an ultra-shallow junction using laser annealing comprising the steps of:

• preparing a silicon substrate having trench type isolation layers to define an active region;
• forming a gate having a stacked structure of a gate insulating layer, a polysilicon layer, a diffusion preventing layer, a metal layer and a hard mask layer on the active region of silicon substrate;
• forming a thin oxide layer on the surface of the silicon substrate and on side of polysilicon layer by performing selective oxidation processes;
• depositing a thin silicon nitride layer as an etching preventing layer on the resulting structure;
• forming a sacrificial spacer on sidewall of gate having the silicon nitride layer thereon;
• forming source/drain regions on the silicon substrate at both sides of gate including the sacrificial spacer;
• removing the sacrificial spacer, the silicon nitride layer and the oxide layer formed on the surface of the silicon substrate;
• doping impurities in low energy to form source/drain extension doping layers on the silicon substrate at both sides of the gate;
• depositing a silicon oxide layer as a reaction preventing layer and an amorphous carbon layer as a laser absorber layer on the resulting structure;
• forming source/drain extension doping layers on inner sides of the source and drain regions by performing laser annealing in an atmosphere of inert gas or under vacuum;
• and
• removing the amorphous carbon layer using an O2, plasma etching process.

A method for forming an ultra-shallow junction using laser annealing comprising the steps of:

• preparing a silicon substrate having isolation layers thereon;
• forming a gate having a stacked structure of a gate insulating layer, a polysilicon layer and a metal layer on the silicon substrate;
• forming source/drain extension doping layers on the silicon substrate regions at both sides of the gate;
• forming a spacer on sidewalls of the gate;
• doping impurities on the silicon substrate at both sides of the gate including the spacer to form source and drain regions;
• depositing a reaction preventing layer and an amorphous carbon layer as an energy absorber layer on the resulting structure;
• forming source and drain regions on the silicon substrate at both sides of gate including the spacer by performing a laser annealing in an atmosphere of inert gas or under vacuum;
• and
• removing the amorphous carbon layer.

A method for forming an ultra-shallow junction using laser annealing comprising the steps of:

• preparing a silicon substrate having trench type isolation layers to define an active region;
• forming a gate having a stacked structure of a gate insulating layer, a polysilicon layer, a diffusion preventing layer, a metal layer and a hard mask layer on the active region of the silicon substrate;
• forming source/drain extension doping layer by doping impurities on silicon substrate at both sides of the gate and by performing a rapid thermal treatment;
• depositing a thin silicon nitride layer as an etching preventing layer on the resulting structure;
• forming a spacer on sidewall of the gate and on the silicon nitride layer deposited thereon;
• doping impurities to form source and drain regions on the silicon substrate at both sides of the gate including the spacer;
• depositing a silicon oxide layer as a reaction preventing layer and an amorphous carbon layer as an energy absorber layer on the resulting structure;
• forming source and drain regions on the silicon substrate at both sides of the gate including the spacer by performing laser annealing in an atmosphere of inert gas or under vacuum;
• and
• removing the amorphous carbon layer using O2, plasma etching.