Semiconductor apparatus and manufacturing method of semiconductor apparatus having a hydrogen increasing portion
Provided is a semiconductor apparatus including: a semiconductor substrate having an upper surface and a lower surface and containing a bulk donor; and a hydrogen increasing portion in which a hydrogen chemical concentration monotonically increases from the upper surface toward the lower surface. The hydrogen increasing portion is provided over 30% or more of a thickness of the semiconductor substrate in a depth direction. A donor concentration in the hydrogen increasing portion is higher than a bulk donor concentration. The semiconductor apparatus can be manufactured by implanting hydrogen ions from the upper surface of the semiconductor substrate to a predetermined first implantation position inside the semiconductor substrate, grinding the lower surface of the semiconductor substrate to remove a part of a region where hydrogen exists, and performing heat treatment on the semiconductor substrate.
1 . A semiconductor apparatus comprising:
a semiconductor substrate having an upper surface and a lower surface and containing a bulk donor;
a hydrogen increasing portion in which a hydrogen chemical concentration of the hydrogen increasing portion monotonically increases from the upper surface toward the lower surface; and
a hydrogen peak portion in which a hydrogen chemical concentration of the hydrogen peak portion includes one or more peaks,
wherein the hydrogen peak portion is directly in contact with the lower surface side of the hydrogen increasing portion,
wherein the hydrogen increasing portion is provided from the upper surface of the semiconductor substrate toward the lower surface of the semiconductor substrate including and over a center depth position of the semiconductor substrate in a depth direction,
wherein a minimum hydrogen chemical concentration of the hydrogen chemical concentration of the hydrogen peak portion is not less than a hydrogen chemical concentration of the hydrogen increasing portion at the center depth position, and
wherein a donor concentration in the hydrogen increasing portion is higher than a bulk donor concentration.
2 . The semiconductor apparatus according to claim 1 , wherein the hydrogen chemical concentration of the hydrogen increasing portion monotonically increases from the upper surface to the lower surface except for a portion where the hydrogen peak portion is provided.
3 . The semiconductor apparatus according to claim 1 , wherein the hydrogen increasing portion has, on a lower surface side of the semiconductor substrate, a portion where a gradient of a hydrogen chemical concentration distribution in a depth direction increases toward the lower surface.
4 . The semiconductor apparatus according to claim 1 , wherein the hydrogen peak portion is provided in a region other than the hydrogen increasing portion.
5 . The semiconductor apparatus according to claim 4 , comprising:
a drift region of a first conductivity type provided in the semiconductor substrate;
a base region of a second conductivity type provided between the upper surface of the semiconductor substrate and the drift region;
an emitter region of a first conductivity type provided between the upper surface of the semiconductor substrate and the base region and having a higher doping concentration than the drift region;
a buffer region of a first conductivity type provided between the lower surface of the semiconductor substrate and the drift region and having a higher doping concentration than the drift region; and
a gate trench portion provided from the upper surface of the semiconductor substrate to a depth position reaching the drift region,
wherein the buffer region includes the hydrogen peak portion, and the hydrogen increasing portion is disposed between a lower end of the gate trench portion and an upper end of the buffer region.
6 . The semiconductor apparatus according to claim 5 , wherein the hydrogen increasing portion is provided from the lower end of the gate trench portion to the upper end of the buffer region.
7 . The semiconductor apparatus according to claim 6 , wherein
a distribution of a hydrogen chemical concentration in the buffer region has a lower tail from the hydrogen peak portion toward the lower surface and an upper tail from the hydrogen concentration peak toward the upper surface,
a hydrogen chemical concentration of the upper tail changes more steeply than a hydrogen chemical concentration of the lower tail, and
the hydrogen chemical concentration of the hydrogen increasing portion monotonically increases from the lower end of the gate trench portion to the upper tail.
8 . The semiconductor apparatus according to claim 1 , wherein the hydrogen increasing portion includes a lifetime adjustment portion that adjusts a lifetime of a carrier.
9 . The semiconductor apparatus according to claim 4 , comprising:
a drift region of a first conductivity type provided in the semiconductor substrate;
an accumulation region of a first conductivity type provided between the upper surface of the semiconductor substrate and the drift region and having a higher doping concentration than the drift region;
a base region of a second conductivity type provided between the upper surface of the semiconductor substrate and the accumulation region;
an emitter region of a first conductivity type provided between the upper surface of the semiconductor substrate and the base region and having a higher doping concentration than the drift region; and
a gate trench portion provided from the upper surface of the semiconductor substrate to a depth position reaching the drift region,
wherein the accumulation region includes the hydrogen concentration peak, and the hydrogen increasing portion is disposed between a lower end of the gate trench portion and the lower surface of the semiconductor substrate.
10 . The semiconductor apparatus according to claim 1 , wherein a hydrogen chemical concentration at an end portion on the lower surface side of the hydrogen increasing portion is higher than a hydrogen chemical concentration at an end portion on the upper surface side of the hydrogen increasing portion.
11 . The semiconductor apparatus according to claim 4 , wherein
the hydrogen peak portion is disposed on the lower surface side of the semiconductor substrate with respect to the hydrogen increasing portion,
the semiconductor apparatus further comprising:
a valley portion of a hydrogen chemical concentration, which is disposed on the lower surface side of the semiconductor substrate with respect to the hydrogen concentration peak.
12 . The semiconductor apparatus according to claim 1 , wherein the hydrogen increasing portion has a variation of ±7% or less with respect to a straight line approximating a distribution shape of the hydrogen chemical concentration of the hydrogen increasing portion.
13 . The semiconductor apparatus according to claim 1 , wherein the hydrogen increasing portion is provided over 30% or more of the thickness of the semiconductor substrate in the depth direction.
14 . The semiconductor apparatus according to claim 13 , wherein the hydrogen increasing portion is provided over 50% or more of the thickness of the semiconductor substrate in the depth direction.
15 . The semiconductor apparatus according to claim 14 , wherein the hydrogen increasing portion is provided over 70% or more of the thickness of the semiconductor substrate in the depth direction.