Semiconductor device, method for manufacturing the same, and electronic device

A semiconductor device comprising:

• a first insulating layer;
• a first oxide semiconductor over the first insulating layer;
• a first insulator over the first oxide semiconductor;
• a second oxide semiconductor over the first insulator;
• a second insulator over the second oxide semiconductor;
• a gate insulating layer over the second insulator;
• and
• a gate electrode layer over the gate insulating layer,
• wherein each of the first oxide semiconductor, the first insulator, the second oxide semiconductor, and the second insulator comprises indium, an element M, and zinc,
• wherein the element M is gallium, aluminum, titanium, yttrium, or tin,
• wherein each of the first oxide semiconductor and the second oxide semiconductor comprises a region with c-axis alignment,
• wherein in each of the first oxide semiconductor and the second oxide semiconductor, number of indium atoms divided by sum of numbers of indium atoms, element M atoms, and zinc atoms is ⅓ or more, and
• wherein in the first insulator, number of zinc atoms divided by sum of numbers of indium atoms, element M atoms, and zinc atoms is ⅓ or less.

A semiconductor device comprising:

• a first insulating layer;
• a first oxide semiconductor over the first insulating layer;
• a first insulator over the first oxide semiconductor;
• a second oxide semiconductor over the first insulator;
• a source electrode layer and a drain electrode layer over the second oxide semiconductor;
• a second insulator over the second oxide semiconductor;
• a gate insulating layer over the second insulator;
• and
• a gate electrode layer over the gate insulating layer,
• wherein each of the first oxide semiconductor, the first insulator, the second oxide semiconductor, and the second insulator comprises indium, an element M, and zinc,
• wherein the element M is gallium, aluminum, titanium, yttrium, or tin,
• wherein each of the first oxide semiconductor and the second oxide semiconductor comprises a region with c-axis alignment,
• wherein in each of the first oxide semiconductor and the second oxide semiconductor, number of indium atoms divided by sum of numbers of indium atoms, element M atoms, and zinc atoms is ⅓ or more,
• wherein in the first insulator, number of zinc atoms divided by sum of numbers of indium atoms, element M atoms, and zinc atoms is ⅓ or less.