Semiconductor CMOS devices and methods with NMOS high-k dielectric formed prior to core PMOS silicon oxynitride dielectric formation using direct nitridation of silicon

A method of fabricating a semiconductor device comprising:

• forming well regions and isolation regions within a semiconductor body defining PMOS and NMOS regions of first and second regions;
• forming an oxide layer on the semiconductor body within the first region and the second region;
• removing the oxide layer from the first region;
• forming a high-k dielectric layer over the first and second regions;
• forming a cap layer over the first and second regions;
• forming a photoresist mask that exposes the cap layer within the PMOS regions of the first and second regions;
• removing the cap layer from the PMOS regions of the first and second regions;
• selectively removing the high-k dielectric layer from the PMOS regions of the first and second regions using the cap layer as a mask;
• removing the photoresist mask;
• removing the cap layer;
• growing a silicon nitride layer on the oxide layer within the PMOS region of the second region and on the semiconductor body within the PMOS region of the first region;
• and
• oxidizing the silicon nitride layer forming a silicon oxynitride layer.

A method of fabricating a semiconductor device comprising:

• selecting first type dielectric characteristics for first type devices within a first region;
• selecting second type dielectric characteristics for second type devices within the first region;
• selecting first type dielectric characteristics for first type devices within a second region;
• selecting second type dielectric characteristics for second type devices within the second region;
• forming a dielectric layer over the device within the first region and the second region with a thickness at least partially selected according to the first type dielectric characteristics within second region;
• removing the dielectric layer from the first region;
• forming a high-k dielectric layer over the first and second regions having a thickness selected according to the selected second type dielectric characteristics within the first region;
• selectively removing the high-k dielectric layer from the first type devices of the first and second regions;
• growing a silicon nitride layer on the first type devices of the first and second regions having a thickness selected according to the first type dielectric characteristics within the first region;
• and
• oxidizing the silicon nitride layer into a silicon oxynitride layer.