Semiconductor device and method for manufacturing the same

A method for manufacturing a semiconductor device which uses a first-conductivity-type low impurity concentration substrate forming a first-conductivity-type low impurity concentration drift layer, and which comprises an element active region and a first electrode thereof formed at a first principal side of said substrate, a second-conductivity-type high impurity concentration layer and a second electrode thereof formed at an outermost portion of a second principal side of said substrate, and a first-conductivity-type high impurity concentration buffer layer formed between said drift layer and said second-conductivity-type high impurity concentration layer, said method comprising the steps of:

• forming said element active region and said first electrode at said first principal side of said substrate and treating said second principal side of said substrate to reduce it to a predetermined thickness;
• irradiating protons from said second principal side and performing an annealing process to thereby form said buffer layer;
• and
• implanting acceptor impurity ions from said second principal side and performing an annealing process to thereby form said second-conductivity-type high impurity concentration layer.

A method for manufacturing a semiconductor device, which uses a first-conductivity-type low impurity concentration substrate forming a first-conductivity-type low impurity concentration drift layer, and which comprises an element active region and a first electrode thereof formed at a first principal side of said substrate, a second-conductivity-type high impurity concentration layer and a second electrode thereof formed at an outermost layer of a second principal side of said substrate, and a first-conductivity-type high impurity concentration buffer layer formed between said drift layer and said second-conductivity-type high impurity concentration layer, said method comprising the steps of:

• forming said element active region and said first electrode at said first principal side of said substrate and treating said second principal side of said substrate to reduce it to a predetermined thickness;
• implanting oxygen ions from said second principal side and performing an annealing process to thereby form said buffer layer;
• and
• implanting acceptor impurity ions from said second principal side and performing an annealing process to thereby form said second-conductivity-type high impurity concentration layer.

A method for manufacturing a semiconductor device that uses a first-conductivity-type low impurity concentration substrate forming a first-conductivity-type low impurity concentration drift layer, and which comprises an element active region and a first electrode thereof formed at a first principal side of said substrate, a second-conductivity-type high impurity concentration layer and a second electrode thereof formed at an outermost layer of a second principal side of said substrate, and a first-conductivity-type high impurity concentration buffer layer formed between said drift layer and said second-conductivity-type high impurity concentration layer, said method comprising the steps of:

• forming said element active region and said first electrode at said first principal side of said substrate and treating said second principal side of said substrate to reduce it to a predetermined thickness;
• implanting donor impurity ions from said second principal side and performing an annealing process of irradiating energy to said second principal side, while cooling said first principal side, to thereby form said buffer layer;
• and
• implanting acceptor impurity ions from said second principal side and performing an annealing process to thereby form said second-conductivity-type high impurity concentration layer.