Abstract: A semiconductor device including: a first transistor which include a first gate stack on a substrate; and a second transistor which includes a second gate stack on the substrate, wherein the first gate stack includes a first ferroelectric material layer disposed on the substrate, a first work function layer disposed on the first ferroelectric material layer and a first upper gate electrode disposed on the first work function layer, wherein the second gate stack includes a second ferroelectric material layer disposed on the substrate, a second work function layer disposed on the second ferroelectric material layer and a second upper gate electrode disposed on the second work function layer, wherein the first work function layer includes the same material as the second work function layer, and wherein an effective work function of the first gate stack is different from an effective work function of the second gate stack.

Abstract: Disclosed herein are a surgical navigation instrument having a needle electrode depth adjusting structure for detecting impedance and a high frequency energy control method using the same. The present invention can detect impedance of tissues while applying a pilot signal to an electrode of a high frequency needle according to impedance conditions of the tissues to detect impedance of the tissues, and determine an applied amount of high frequency energy output to high frequency needles according to the detected impedance, thereby reducing patients' pains, maximizing treatment effect, and reducing treatment time according to high frequency energy applied to various depths at the same treatment point when performing a surgical procedure with the same or different treatment parameters according to disease symptoms while selecting the insertion number of high frequency needles, which can be adjusted in penetration depth, into the skin.

Abstract: Disclosed herein is a surgical navigation instrument having a temperature sensor. The surgical navigation instrument can easily perform an autoclave action to remove microorganisms using saturated steam with respect to a part which can be contaminated during treatment, and enhance convenience in replacement of a grip part and the electrodes of the handpiece which are consumables, since a handpiece and electrodes are detachably screw-coupled with each other.