Why thick metal can increase Q of inductor?

In CMOS design, designer often use thick metal layers to design inductor to obtain high Q ? due to the resistance is smaller? Thanks .

Because series resistance is decreased,losses are decreased...

Thanks a lot . I understand that R= ρ*L/S
S is the cross section area
It seems that the resistance can be reduced by increase area , right?

But when frequency goes high , due to skin effect, the current is mainly on the surface, am I right? so still this thicker metal can increase the Q?

Most inductor's Q has a sort of bell shape vs. frequency, due to the competing mechanism of omege* L and Rs. Increase thickness only helps to certain degree due to the skin depth. Above a high enough f, increase thickness will no longer help.

You're right but you can not increase the frequency as you wish too with CMOS process, so skin effect may be negligible within moderate frequencies unless if you use very particular
CMOS process.