Semiconductor light emitting device, semiconductor wafer with first and second portions with different lattice polarities

A semiconductor wafer, comprising:

• a substrate;
• a light emitting layer arranged with the substrate in a first direction;
• a first semiconductor layer provided between the substrate and the light emitting layer, the first semiconductor layer including a first portion and a second portion, the first portion and the second portion including a nitride semiconductor, the first portion having a first lattice polarity, and the second portion having a second lattice polarity different from the first lattice polarity;
• a second semiconductor layer provided between the first semiconductor layer and the light emitting layer, the second semiconductor layer being of a first conductivity type;
• a third semiconductor layer of the second conductivity type, the light emitting layer being provided between the second semiconductor layer and the third semiconductor layer;
• and
• an In-containing layer provided between the second semiconductor layer and die light emitting layer, the In-containing layer including a nitride semiconductor including In,
• the light emitting layer including a nitride semiconductor including In,
• a composition ratio of In in the In-containing layer being different from a composition ratio of In in the light emitting layer,
• a lattice length of the In-containing layer in a-axis direction being not less than 0.1% greater than a lattice length of the second semiconductor layer in the a-axis direction, and
• a difference of the lattice length of the In-containing layer in the a-axis direction and the lattice length of the light emitting layer in the a-axis direction is not more than 0.1%.