Method of forming nitrogen implanted ultrathin gate oxide for dual gate CMOS devices
AssigneesSharp Laboratories of America, Inc., Sharp Kabushiki Kaisha
InventorsYoshi Ono, Yanjun Ma
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Abstract
A method of forming a nitrogen-implanted gate oxide in a semiconductor device includes preparing a silicon substrate; forming an oxide layer on the prepared substrate; and implanting N+ or N2+ ions into the oxide layer in a plasma immersion ion implantation apparatus.
Claims21
A method of forming a nitrogenimplanted gate oxide in a semiconductor device, comprising:
- preparing a silicon substrate;
- forming an oxide layer having a thickness of between 1.0 nm and 10 nm on the prepared substrate;
- and
- implanting N+ ions into the oxide layer in a plasma immersion ion implantation apparatus, wherein said implanting includes electrically biasing the prepared substrate and implanting N+ ions at an energy of between 0.1 keV and 2.0 keV, at a dose of between 1·1013 cm−2 and 1·1016 cm−2.
A method of forming a nitrogen-implanted gate oxide in a semiconductor device, comprising:
- preparing a silicon substrate;
- forming an oxide layer having a thickness of between 1.0 nm and 10 nm on the prepared substrate;
- and
- forming a barrier layer at the upper surface of the oxide layer by electrically biasing the silicon substrate and implanting ions, whereby said barrier layer blocks diffusion of boron from subsequently formed layers.
The method of claim, 3, wherein said silicon substrate is negatively biased, whereby positive ions are attracted to the silicon substrate.
A method of forming a nitrogen-implanted gate oxide in a semiconductor device, comprising:
- preparing a silicon substrate;
- forming an oxide layer having a thickness of between 1.0 nm and 10 nm on the prepared substrate;
- placing the prepared substrate within a vacuum chamber on a chuck that is biased with voltage pulses;
- and
- creating a plasma discharge within the vacuum chamber, wherein said plasma discharge includes material to be implanted, whereby the material is attracted to the prepared substrate on the biased chuck and implated into the oxide layer.
A method of providing a gate oxide in a semiconductor device comprising the following steps:
- preparing a silicon substrate for the formation of a device having a channel region and a polysilicon gate which, when completed, includes boron in the gate polysilicon;
- forming an oxide layer having a thickness of between 1.0 nm and 10 nm on the prepared substrate, said oxide layer to become the gate oxide for said device when said device is completed;
- implanting N+ ions into the oxide layer in a plasma immersion ion implantation apparatus, said implanting includes implanting N+ ions at an energy of between 0.1 keV and 2.0 keV, such that nitrogen is embedded in said oxide layer to block the diffusion of boron from the gate into the channel region of the device.
Dependencies are inferred from the claim text.