The present perfect subjunctive tense is constructed by using the present subjunctive form of the irregular verb haber with a past participle:
 

The past participle does not change forms when it is used in the present perfect subjunctive tense.  For example, él haya leído, tú hayas leído, ellos hayan leído, etc.

Like other subjunctive tenses, the present perfect subjunctive is found in the subordinate clause of a sentence.   Specifically, the present perfect subjunctive is found in subordinate clauses that express past actions and follows a verb or expression that requires a subjunctive:  ¡Espero que el cocinero se haya lavado las manos! (I hope the cook washed his hands!).