Dear Ian, thank you very much for your reply.
I am using Ar gas and gold target. so could you tell me, if there is no
leak, the plasma should be in blue? whatever in low temperature or at room
temperature? if I see the purple plasma at room temperature, that means I
got N2 leaks into my chamber?
Best regards, Huisheng


On 7/10/06, Ian Burnett  wrote:
>
> Hi Huisheng, It sounds like  you have  a leak in the chamber at room temp
> and the pink colour of an N2 plasma is adding  to the blue of the Ar? you
> are using to sputter. What is the leak up rate at room temperature?
> Ian Burnett
>
> ----- Original Message -----
> From: "Huisheng JIAO" 
> To: 
> Sent: Monday, July 10, 2006 9:48 AM
> Subject: [mems-talk] Plasma colour
>
>
> > Dear All:
> >
> > Anybody can advise me the relationship between the colour of plasma and
> the
> > temperature of the vacuum chamber? When sputtering at room temperature,
> the
> > plsama shows purple colour; but when the chamber cooled by liquid
> nitrogen,
> > plasma changes to bule colour. what is the reason? Thanks in advance,