EFFECT OF CHANNELING OF HALO ION-IMPLANTATION ON THRESHOLD VOLTAGE SHIFT OF METAL-OXIDE-SEMICONDUCTOR FIELD-EFFECT TRANSISTOR

In this letter, we report threshold voltage shift of metal oxide semic onductor field effect transistor (MOSFET) after the halo ion implantat ion process. Although halo implantation can significantly reduce the s hort channel effect, it causes a threshold voltage shift of a long cha nnel device due to dopant channeling through polycrystalline silicon g rain boundary. Although the chemical vapor deposited (CVD) cap oxide o n polycrystalline silicon gate was used as a blocking layer of dopant, threshold voltages shift clearly indicate dopant channeling through p olycrystalline silicon. To avoid a channeling problem, a thicker cap o xide layer or lower halo implantation energy is necessary. (C) 1996 Am erican Institute of Physics.