10. STOCK-BASED COMPENSATION (Tables)

6 Months Ended

Sep. 30, 2022

STOCK-BASED COMPENSATION

Summary of stock option activities

			Weighted
		Number of Shares	Average	Weighted
	Shares	Underlying	Remaining	Average
	Available for	Options	Contractual	Exercise		Intrinsic
	Grant	Outstanding	Life (Years)	Price		Value
Balance at March 31, 2022	4,535,663	8,590,675		$	6.07
Granted	(750,803)	750,803		$	4.01
Exercised	—	—		$	—	$	—
Forfeited	279,450	(736,517)		$	5.53
Balance at September 30, 2022	4,064,310	8,604,961	5.56	$	5.94
Options vested and exercisable		5,625,224	3.99	$	6.00	$	—
Options vested and expected to vest		8,499,457	5.51	$	5.94	$	—

Summary of stock-based compensation expense by line item

	Three Months Ended September 30,				Six Months Ended September 30,
	2022		2021		2022		2021
	(In Thousands)				(In Thousands)
Cost of revenues	$	49	$	64	$	109	$	134
Research and development		390		418		741		888
Selling, general and administrative		222		234		449		517
Total	$	661	$	716	$	1,299	$	1,539