Graded implantation of oxygen and/or nitrogen constituents to define buried isolation region in semiconductor devices
AssigneesSharp Microelectronics Technology, Inc., Sharp Kabushiki Kaisha
InventorTatsuo Nakato
Life of this patent
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Abstract
A graduated concentration profile is used for defining a buried isolation region in a semiconductor device. Smaller concentrations of dielectric-defining particles are used for implantation at the deepest levels of the isolation region in order to reduce the defect density in an overlying epi layer.
Claims13
A semiconductor device comprising an epi layer, an isolation region and a bulk layer arranged one below the other in the recited order where the isolation region has a top boarding the epi layer and a bottom boarding the bulk layer and is composed of a semiconductor material and one or more insulation-forming particles and where a concentration of the particles does not approximate a Gaussian distribution of the particles within the isolation region and the concentration of particles decreases substantially from the top of the isolation region to the bottom of the isolation region.
A semiconductor device comprising:
- an epi layer;
- a bulk layer;
- and
- an isolation region, located between the epi layer and the bulk layer, composed of a semiconductor material and one or more insulation-forming particles and is divided into a first region and a second region where:
- the first region is located adjacent to the epi layer and has a concentration of the particles to form a stoichiometric insulator in the first region, and
- the second region is at least equal in size to the first region, is located adjacent to both the first region and the bulk layer and has a concentration of the particles less than the concentration of particles required to form a stoichiometric insulator.
Dependencies are inferred from the claim text.