Patent ID: 7038250
Filing Date: 2006-05-02
Classification: H01L

Abstract:
1. A semiconductor device comprising: a collector contact layer made of an n-type GaAs layer; a first collector layer formed on said collector contact layer and made of an n-type GaAs layer; a second collector layer formed on said first collector layer and made of a p-type GaAs layer; a third collector layer formed on said second collector layer and made of an n-type InGaP layer; a fourth collector layer formed on said third collector layer and made of an n-type InGaP layer having an impurity concentration higher than that of said third collector layer; a fifth collector layer formed on said fourth collector layer and made of an n-type GaAs layer; a base layer formed on said fifth collector layer and made of a p-type GaAs layer; and an emitter layer formed on said base layer and made of an n-type InGaP layer.