公开(公告)号：JPH10242389A

公开(公告)日：1998-09-11

申请号：JP2700998

申请日：1998-02-09

Applicant: IBM

Inventor： EDWARD J NOWAKU ,  TEIEN SHAOUEI ,  MIN H TON

IPC: H01L27/04 ,  H01L21/822 ,  H01L29/8605

Abstract: PROBLEM TO BE SOLVED: To provide a noise separation burial resistor that satisfies the requirements of a low-noise analog design requiring a properly controlled ohm resistor. SOLUTION: An electric field shielding is provided between a buried resistor and a substrate to separate the buried resistor from the noise of a substrate by a standard buried resistor layout and a mask sequence with two exceptions. First, the buried resistor is not simply arranged at the region of a P well 13 but arranged at the region of an N well 4. Second, to electrically separate the buried resistor from the N well 14, a boron impregnant is added via the buried resistor mask and the P well 13 is formed inside the N well 14, thus electrically connecting the N well 14 to the noiseless ground. The P well 13 inside the N well 14 is left in floating state.