SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF

The high voltage transistor includes a first impurity layer, a second impurity layer formed inside the first impurity layer, so as to put the second impurity layer between them, a pair of third impurity layers and fourth impurity layers formed inside the first impurity layer, a fifth impurity layer formed from the uppermost surface of the first impurity layer to the inside of the first impurity layer so as to protrude along the main surface in the direction where the second impurity layer is disposed, and a conductive layer formed above the uppermost surface of the second impurity layer. The concentration of the impurity in the fourth impurity layer is higher than the concentration of the impurity in the third and the fifth impurity layers, and the concentration of the impurity in the fifth impurity layer is higher than the concentration of the impurity in the third impurity layer.