STOCK-BASED COMPENSATION (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Feb. 28, 2022	Feb. 28, 2021	Feb. 28, 2022	Feb. 28, 2021
Total stock-based compensation	$ 880	$ 271	$ 2,186	$ 798
Cost of Sales
Total stock-based compensation	90	14	248	45
Selling, General and Administrative
Total stock-based compensation	487	194	1,259	593
Research and Development
Total stock-based compensation	$ 303	$ 63	$ 679	$ 160

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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