I think it's important in EN to add the 'high', which is implicit in the FR.

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Note added at 13 hrs (2018-09-18 18:11:34 GMT)
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I had hoped I wouldn't have to spell it out, but here goes:

In FR, when we say 'à température', depending on the context, it is automatically implied that it is an elevated temperature; 'cold' would just be the absence of temperature.

In EN, however, we have to specify that it is low- or high-temperature; only in certain instances can we say 'temperature' alone (where it is neither high nor low, e.g. 'temperature control'; or where it refers to some specific known temperature, e.g. ambient: "must be brought up to temperature before service"

So here, if we were just to say 'temperature formation', the only way that could be understood would be 'forming a temperature'; 'forming at temperature' would be closer to the FR formulation, but inelegant in EN.

Hence my suggestion probably makes best technical sense here — and I know from personal knowledge of semiconductors and experience that this would not of course be referring to LOW-temperature formation! Especially, of course, because the S/T later speaks of 'cooling down'.