Semiconductor integrated circuit device, magnetic disk storage device, and electronic apparatus

A semiconductor integrated circuit device comprising:

• a p-type substrate to which a ground voltage is applied;
• a floating-type NMOS FET which is integrated on the p-type substrate and to which a negative voltage lower than the ground voltage is applied;
• a p-type contact region which applies the ground voltage to the p-type substrate;
• and
• a double diffusion-type PMOSFET which is integrated on the p-type substrate so as to impose the p-type contact region and be adjacent to the floating-type NMOS FET, wherein
• the floating-type NMOS FET includes:
• an n-type buried layer which is buried in the p-type substrate;
• a high voltage n-type well which is formed on the n-type buried layer and floats electrically;
• a p-type drift region which is formed in the n-type well;
• an n-type drain region and an-type source region which are formed in the p-type drift region;
• and
• a gate electrode which is formed on a channel region interposed between the n-type drain region and the n-type source region, and wherein
• the high voltage n-type well includes an n-type tunnel region, with a higher impurity concentration than that of the high voltage n-type well, inside a peripheral region formed so as to surround the p-type drift region, and wherein
• the double diffusion-type PMOSFET includes:
• a second n-type buried layer which is buried in the p-type substrate;
• a second high voltage n-type well which is formed on the second n-type buried layer and to which a power supply voltage higher than the ground voltage is applied;
• a second n-type source region which is formed in the second high voltage n-type well;
• a second p-type drift region which is formed in the second high voltage n-type well;
• a p-type drain region which is formed in the second p-type drift region;
• and
• a second gate electrode which is formed on a channel region interposed between the second n-type source region and the p-type drain region.