| 摘要 |
An LDMOS(laterally diffused metal oxide semiconductor) for an RF power amplifier is provided to minimize the capacitance between a drain region and a poly gate by forming a field oxide layer in an offset region. A substrate(21) of first conductivity type is prepared on which an epitaxial layer(22) of first conductivity type is grown. A poly gate(28) is formed on a predetermined surface of the epitaxial layer. A high-density source region(31) of second conductivity type is aligned with one lateral surface of the poly gate. A high-density drain region(32) of second conductivity type is formed in the epitaxial layer, separated from the other lateral surface of the poly gate by a predetermined distance. A low-density offset region of second conductivity type is formed in the epitaxial layer between the other lateral surface of the poly gate and the drain region. A field oxide layer(26) is formed on the low-density offset region of second conductivity type, separated from the poly gate by a predetermined distance. A poly field plate(29) is formed on the field oxide layer. A metal field plate is connected to the poly field plate, connected to the source region. The offset region includes first and second offset regions(25,30). The first offset region is formed under the field oxide layer, having a greater width than that of the field oxide layer. The second offset region is aligned with the other lateral surface of the poly gate.
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