Light emitting device and manufacturing method thereof

A method of manufacturing a light emitting device comprising:

• forming a first electrode;
• forming a light emitting layer over the first electrode;
• and
• forming a second electrode over the light emitting layer,
• wherein the light emitting layer contains oxygen as an impurity at a concentration equal to or less than 1×1019cm−3, and
• wherein the light emitting layer is formed by evaporation in which an evaporation material is heated by resistance heating.

A method of manufacturing an active matrix drive light emitting device comprising:

• forming a thin film transistor in a pixel portion;
• forming an interlayer insulating film over the thin film transistor;
• forming a first electrode over the interlayer insulating film;
• forming a light emitting layer over the first electrode;
• forming a second electrode over the light emitting layer;
• and
• forming a protective film over the second electrode,
• wherein the light emitting layer contains oxygen as an impurity at a concentration equal to or less than 1×1019cm−3.

A method of manufacturing an active matrix drive light emitting device comprising:

• forming a thin film transistor in a pixel portion;
• forming an interlayer insulating film over the thin film transistor;
• forming a first electrode over the interlayer insulating film;
• forming a light emitting layer over the first electrode;
• and
• forming a second electrode over the light emitting layer,
• wherein the light emitting layer contains oxygen as an impurity at a concentration equal to or less than 1×1019cm−3, and
• wherein the light emitting layer is formed by evaporation in which an evaporation material is heated by resistance heating.