Semiconductor device and method of fabricating the same

A method of fabricating a semiconductor device, which is formed by forming a bipolar transistor including a base electrode, a collector electrode, and an emitter electrode, a CMOS transistor including a first gate electrode, a first drain electrode, and a first source electrode, and a DMOS transistor including a second gate electrode, a second drain electrode, a body electrode, and a second source electrode, on a semiconductor substrate and are separated from each other in a transverse direction, the method comprising:

• providing the semiconductor substrate including a first active region, on which the bipolar transistor will be formed, a second active region, on which the CMOS transistor will be formed, and a third active region, on which the DMOS transistor will be formed;
• forming a gate insulating layer pattern on portions of the substrate, on which the first gate electrode and the second gate electrode will be formed;
• forming a first polysilicon layer on an entire substrate including the gate insulating layer pattern;
• injecting a high concentration of first conductive type impurities as ions onto portions of the first polysilicon layer, on which the collector electrode, the first gate electrode, and the body electrode will be formed;
• injecting a high concentration of second conductive type impurities onto portions of the first polysilicon layer, on which the base electrode and the second drain electrode will be formed;
• forming the collector electrode, the base electrode, the first gate electrode, the body electrode, and the second gate electrode by patterning the first polysilicon layer;
• performing a first thermal treatment of the semiconductor substrate so as to form first conductive type first impurity regions in the substrate under the collector electrode and under the body electrode, and second conductive type first impurity regions in the substrate under the base electrode and the second drain electrode;
• injecting a low concentration of first conductive type impurities as ions onto the collector electrode, the first gate electrode, and both sides of the first gate electrode;
• injecting a low concentration of second conductive type impurities into the base electrode;
• sequentially injecting a low concentration of first conductive type impurities and a low concentration of second conductive type impurities as ions onto the body electrode, the second gate electrode, and portions between the body electrode and the second gate electrode;
• performing a second thermal treatment of the substrate so as to form a second conductive type second impurity region between the first impurity regions of the second conductive type in the first active region, to form first conductive type second impurity regions on both sides of the first gate electrode in the second active region, and to form a second conductive type second impurity region between the second gate electrode and the body electrode in the third active region and a first conductive type second impurity region surrounding the second conductive type second impurity region;
• forming a second polysilicon layer on an entire substrate including structures formed on the substrate;
• injecting a high concentration of the first conductive type impurities as ions onto portions of the second polysilicon layer, on which the emitter electrode, the first source electrode, and the first drain electrode will be formed, and performing a third thermal treatment of the substrate;
• and
• forming the emitter electrode, the first source electrode, the first drain electrode, and the second source electrode by patterning the second polysilicon layer.