If the metal is deposited at room temperature, you could try these sticky graphite pads which are used to fixate microscopy samples. At elevated temperature, i suppose you will require either clamping or use a setup in which the substrate is on the bottom and does not need that.

You can use vacuum compatible kepton tape for room temperature as well as for higher temperature deposition (but not more than 200 degree Celsius).

Frédéric Lacour : like these:

https://www.2spi.com/item/z05073/adhesive-discs-tabs/

Maybe there are also cheaper options, search for adhesive carbon discs.

A more exotic way is to weld the sample to a base using a metal with a low melting temperature, see: https://en.m.wikipedia.org/wiki/Field%27s_metal

Advantages are the better thermal contact and the absence of a gap which may be important in UHV.

A more exotic way is to weld the sample to a base using a metal with a low melting temperature, see: https://en.m.wikipedia.org/wiki/Field%27s_metal

Advantages are the better thermal contact and the absence of a gap which may be important in UHV.