What is high breakthrough field?

[DirecSa]

I have read in the following article the expression "high breakthrough field": https://link.springer.com/article/10.1557/PROC-871-I9.6

I tried to find out in the internet what is the definition of that and what it refers to in the transistors but I couldn't find anything!

Thank you in advance!

 

[Baluncore]

The paper is behind a paywall.
The paper reports on the design of MOSFET transistors for use in thin film displays.

When turned off, the breakdown voltage of the transistor must withstand the maximum display voltage across a thin dielectric. The dielectric must withstand a high electric field gradient without breaking down.