Compound Semiconductors for Low-Power p-Channel Field-Effect Transistors

Research in n-channel field-effect transistors based upon III-V compound semiconductors has been very productive over the last 30 years, with successful applications in a variety of high-speed analog circuits. For digital applications, complementary circuits are desirable to minimize static power consumption. Hence, p-channel transistors are also needed. Unfortunately, hole mobilities are generally much lower than electron mobilities for III-V compounds. This article reviews the recent work to enhance hole mobilities in antimonide-based quantum wells. Epitaxial heterostructures have been grown with the channel material in 1-2 compressive strain. The strain modifies the valence band structure, resulting in hole mobilities as high as 1500 cm2Vs. The next steps toward an ultra-low-power complementary metal oxide semiconductor technology will include development of a compatible insulator technology and integration of n- and p-channel transistors.