Method and apparatus for power device with multiple doped regions

A method of manufacturing a semiconductor device, comprising:

• preparing a substrate of a first conductivity type;
• forming a well region in the substrate, the well region having a second conductivity type opposite to the first conductivity type;
• forming a first mask layer over the substrate, the first mask layer including a first hole;
• implanting a first implant and a second implant through the first mask layer and into the well region to form a first doped region, the first doped region comprising a lower portion having the first conductivity type, and an upper portion stacked on the lower region and having the second conductivity type;
• removing the first mask layer from the substrate;
• forming a second mask layer over the substrate, the second mask layer including a second hole;
• implanting the first implant and the second dopant through the second mask layer and into the well region to form a second doped region, such that the first doped region and the second doped region are vertically and horizontally offset from each other, the second doped region comprising a lower portion having the first conductivity type and an upper portion stacked on the lower region and having the second conductivity type;
• and
• removing the second mask layer from the substrate.

A method of manufacturing a semiconductor device, comprising:

• preparing a substrate of a first conductivity type;
• forming a first well region in a substrate, the first well region having a second conductivity type opposite to the first conductivity type;
• forming a first epitaxial layer of the first conductivity type on the substrate;
• forming a second well region in the first epitaxial layer, the second well region having the second conductivity type;
• forming a first mask layer over the first epitaxial layer, the first mask layer including a first hole;
• implanting a first implant and a second implant through the first mask layer and into the second well region to form a first doped region, the first doped region comprising a lower portion having the first conductivity type and an upper portion stacked on the lower region and having the second conductivity type;
• removing the first mask layer from the first epitaxial layer;
• forming a second epitaxial layer of the first conductivity type on the first epitaxial layer;
• forming a third well region in the second epitaxial layer, the third well region having the second conductivity type, the first, second, and third well regions forming a continuous well region;
• forming a second mask layer over the second epitaxial layer, the second mask layer including a second hole;
• implanting the first implant and the second dopant through the second mask layer and into the third well region to form a second doped region such that the first doped region and the second doped region are vertically and horizontally offset from each other, the second doped region comprising a lower portion having the first conductivity type and an upper portion stacked on the lower region and having the second conductivity type;
• and
• removing the second mask layer from the second epitaxial layer.

A method of manufacturing a semiconductor device, comprising:

• preparing a substrate of a first conductivity type;
• forming a well region in the substrate, the well region having a second conductivity type different to the first conductivity type;
• forming a first mask layer over the substrate, the first mask layer including a first hole;
• implanting a first implant and a second implant through the first mask layer and into the well region to form a first doped region, the first doped region comprising a lower portion having the first conductivity type, and an upper portion stacked on the lower region and having the second conductivity type;
• forming a second mask layer over the substrate, the second mask layer including a second hole;
• and
• implanting the first implant and the second dopant through the second mask layer and into the well region to form a second doped region, such that the first doped region and the second doped region are vertically and horizontally offset from each other, the second doped region comprising a lower portion having the first conductivity type and an upper portion stacked on the lower region and having the second conductivity type.