I am trying to run a HSPICE simulation which involves testing for a sense amp Vth mismatch on the circuit.
I want to make a graph Voltage/Time with multi lines of different Vt's. (increment sweep, not monte carlo)

Hspice manual has an syntax for mismatch but, not threshold voltage(Vt)

There's the manual syntax for mismatch below
It might be helpful for you

How can I sweep Vt with increment "ΔV(vdelta)" and make data table?

###############################################
Note:
If more than one DCMatch analysis is specified per simulation, only the last
statement is used.
Example 1
In this example, HSPICE reports DCMatch variations on the voltage of node 9,
the voltage difference between nodes 4 and 2, and on the current through the
source VCC.
.DCMatch V(9) V(4,2) I(VCC)
Example 2
In this example, the variable XVal is being swept in the DC command from 1k
to 9k in increments of 1k. DCMatch variations are calculated for the voltage on
node out. Tables with DCMatch results are generated for the set XVal={1K, 4K,
7K, 9K}.
.DC XVal Start=1K Stop=9K Step=1K
.DCMatch V(out) Interval=3
################################################
Referring this syntax, I made code but it didn't work
(vdelta means increment Vt to sweep, used DELVTO to shift Vt)

Code:
.DC vdelta start=0.0 stop=1 step=0.1
~~~~~~~
*SENSE AMPLIFIER
MSN1 (node) (node) (node) (node) NMOS1 W=130n L=65n DELVTO=vdelta
~~~~~~~
.TRAN 0.01ns 20ns start=0ns