Transistor, semiconductor device, and electronic device
摘要
說明書
The low-concentration p-type impurity regions 284 can be formed in such a manner that an impurity element is added with the use of the electrode 287 as a mask after the formation of the electrode 287 and before the formation of the sidewall 288. In other words, the low-concentration p-type impurity regions 284 can be formed in a self-aligned manner. After the sidewall 288 is formed, the high-concentration p-type impurity regions 285 are formed. Note that the low-concentration p-type impurity regions 284 have the same conductivity type as the high-concentration p-type impurity regions 285, and have a lower concentration of the impurity imparting the conductivity type than the high-concentration p-type impurity regions 285. The low-concentration p-type impurity regions 284 are not necessarily provided depending on circumstances.
The transistor 281 is electrically isolated from other transistors by an element isolation layer 414. The element isolation layer can be formed by a local oxidation of silicon (LOCOS) method, a shallow trench isolation (STI) method, or the like.
