Hi Wilson,
I have not hear from you on my question.
Here is the update on my investigation:
Please ignore question 2 and 3, once the load is connected across the H-bridge, the problems with inconsistent rise time goes away.
There are few more question on the part:
1) Under 6.5 Electrical Characteristics, the Output dead time is specified as 380ns with remark (Observed tdead depends on IDRIVE setting), what is the IDRIVE setting for 380ns? Is this 380ns an observed dead time with particular IDRIVE setting? What is the guaranteed dead time without considering the IDRIVE setting ?
2) Attached is the waveform measured comparing GL1, GH1 and output. It takes about 350ns (dead time) for GL1 to starts to rise after GH1 gone low completely.
My assumption is I should see around 150ns ( as mentioned in page 21) in this case. This is measured with DRV8701 eval board.
. 
3) When pulse width is reduce, I observed the fall time increase with same IDRIVE setting. Attached are the waveform with max IDRIVE setting:
Trace C2 : EN
Trace C3 : Output (SH1)
Trace C4 :GH1
