Inductive load driving circuit

A photodiode having:

• a p type first semiconductor layer,
• an n type second semiconductor layer formed directly on said first semiconductor layer and containing an n type electroconductive impurity at a low concentration,
• an n type third semiconductor layer that contains an n type electroconductive impurity at a medium concentration and is formed shallower than said second semiconductor layer in the main plane of the second semiconductor layer,
• an n type fourth semiconductor layer that contains an n type electroconductive impurity at a high concentration and is formed shallower than said third semiconductor layer in the main plane of the third semiconductor layer in a layout subdivided by said third semiconductor layer in at least one cross section, and
• a metal-containing electroconductive layer formed on said fourth semiconductor layer in the same layout as the fourth semiconductor layer.

A photodiode having:

• a first semiconductor layer of a first electroconductivity type,
• a second semiconductor layer of a second electroconductivity type formed on said first semiconductor layer,
• a third semiconductor layer of the second electroconductivity type and having a higher impurity concentration than said second semiconductor layer that is formed partially in the main plane of said second semiconductor layer,
• a metal silicide layer formed on said third semiconductor layer, and
• a first electrode electrically connected to said metal silicide layer and said third semiconductor layer.