Signal transmission device

A signal transmission device having a capacitor coupler, comprising:

• a semiconductor substrate;
• a first insulating film disposed above the semiconductor substrate;
• a lower electrode disposed above the semiconductor substrate across a portion of the first insulating film;
• an upper electrode disposed opposite the lower electrode across the first insulating film, forming a capacitor together with the lower electrode, and configured to be applied with a voltage higher than a voltage applied to the lower electrode;
• a second insulating film disposed above the first insulating film and covering at least a portion in an outer peripheral portion of the upper electrode that is in contact with the first insulating film;
• and
• a third insulating film disposed above the second insulating film and made of an insulating organic material, wherein
• the second insulating film is made of a material having a higher insulation breakdown voltage than the third insulating film,
• the upper electrode has a thickness of 3.0 μm or more,
• a surface of the upper electrode located opposite the first insulating film is defined as an upper surface, a surface of the upper electrode facing the first insulating film is defined as a lower surface, a surface of the upper electrode connecting the upper surface and the lower surface is defined as a side surface, and a thickness of a portion of the second insulating film covering the side surface of the upper electrode is 1.3 μm or more, and
• when viewed from a normal direction to a surface of the semiconductor substrate on which the first insulating film is disposed, an entire area of the lower electrode is disposed inside an outer periphery of the upper electrode.

A signal transmission device having a capacitor coupler, comprising:

• a semiconductor substrate;
• a first insulating film disposed above the semiconductor substrate;
• a lower electrode disposed above the semiconductor substrate across a portion of the first insulating film;
• an upper electrode disposed opposite the lower electrode across the first insulating film, forming a capacitor together with the lower electrode, and configured to be applied with a voltage higher than a voltage applied to the lower electrode;
• a second insulating film disposed above the first insulating film and covering at least a portion in an outer peripheral portion of the upper electrode that is in contact with the first insulating film;
• and
• a third insulating film disposed above the second insulating film and made of an insulating organic material, wherein
• the second insulating film is made of a material having a higher insulation breakdown voltage than the third insulating film,
• the upper electrode has a slit in a vicinity of an outer periphery of the upper electrode, and
• the slit extends along the outer periphery of the upper electrode.